Some WriteFreely instances are completely private, and thus have no need for public-
oriented features like Web Monetization. Like federation, this gives admins control
over whether or not the feature is enabled for users.

Ref T773

Add generic Oauth allow_logout option

Signed-off-by: prichier <pascoualito@gmail.com>

This moves logic for determining whether or not to show a "Sign up" page
on /signup (i.e. because the `/` route shows another, non-signup page)
into the AppCfg.SignupPath() method. It also changes various signup
links to use this value.

This adds gopher support to WriteFreely -- both single- and multi-user
instances. It is off by default, but can be enabled with the new
`gopher_port` config value in the `[server]` section.

When enabled, multi-user instances will show all public blogs at
gopher://[host]:[gopher_port]/ -- otherwise, blogs are accessible at
gopher://[host]:[gopher_port]/[blog]/

This is just a proof of concept for now. We still need to handle some
edge cases and different configurations, like private instances.

Ref T559

This adds a new config option that signifies the admin doesn't need to
see deeply technical things, like application resource usage. In the
[app] section, set forest = true to enable this.

Ref T694

includes cache of latest version and page to view if updates are
available with a link to the latest update's release notes and a link to
check for the latest update now, refreshing the cache manually.

This shows Drafts in the SimpleNav menu, when both enabled. It also
hides Drafts in the non-SimpleNav menu when disabled.

Ref T679

This adds a new config value: `chorus` that signifies an instance is
more about the Reader view than individual blogs / writers. When
enabled, user navigation will show on all pages, including About,
Reader, and Privacy (ref T680).

It also uses different collection templates that keep the instance-wide
navigation at the top of the page, instead of the author's name --
again, branded more for the collective than the individual.

Ref T681

This shows the Blogs page instead of the Editor to logged in users on
the `/` path when the new `simple_nav` config option is enabled.

Ref T680

Ref T677

This adds a new `wf_modesty` config option that removes the copious
mentions of WriteFreely in places like the About page and site
footers.

WriteFreely remains boastful and bumptious by default; but enabling
the modesty option will tone it down and likely lead to less confusion
among average users.

Ref T676

This adds a new `default_visibility` config value that lets an instance
admin set the visibility of newly created collections.

Ref T675

This adds a new config option in the `[server]` section: `autocert`.
When true, WF will automatically generate certificates instead of using
ones from the provided cert path. However, all generated certificates
will be stored in the configured `tls_cert_path`.

Ref T542

This is the start of all changes needed to support entirely private
instances, where all blogs are only visible to other authenticated users
on an instance (ref T576). It begins by changing how Handler methods check an
endpoint's permissions.

- Renames UserLevelLEVEL consts to UserLevelLEVELType
- Adds UserLevelLEVEL funcs with same names as previous consts. Each
  returns a UserLevel
- Adds a new UserLevelReader that restricts access based on app
  configuration. This is now used on collections and posts.
- Changes routing a bit so static files are always accessible

This adds a new `landing` value in the [app] section of config.ini.
If non-empty, unauthenticated users on multi-user instances will be
redirected to the path given there.

This closes T574

This adds a new `landing` value in the [app] section of config.ini.
If non-empty, unauthenticated users on multi-user instances will be
redirected to the path given there.

This closes T574

This adds new configuration values that specify the parent directory of
application resources:

- templates_parent_dir
- static_parent_dir
- pages_parent_dir
- keys_parent_dir

For any values not specified, the application will default to the
current directory.

This closes T560

This adds new configuration values that specify the parent directory of
application resources:

- templates_parent_dir
- static_parent_dir
- pages_parent_dir
- keys_parent_dir

For any values not specified, the application will default to the
current directory.

This closes T560

This includes:

- A new `user_invites` config value that determines who can generate
  invite links
- A new page for generating invite links, with new user navigation link
- A new /invite/ path that allows anyone to sign up via unique invite
  link, even if registrations are closed
- Tracking who (of registered users) has been invited by whom

It requires an updated database with `writefreely --migrate` in order to
work.

This closes T556

This adds a "Reader" section of the site for admins who want to enable
it for their instance. That means visitors can go to /read and see who
has publicly shared their writing. They can also follow all public posts
via RSS by going to /read/feed/. Writers on an instance with this
`local_timeline` setting enabled can publish to the timeline by going
into their blog settings and choosing the "Public" visibility setting.

The `local_timeline` feature is disabled by default, as is the Public
setting on writer blogs. Enabling it adds a "Reader" navigation item and
enables the reader endpoints. This feature will also consume more
memory, as public posts are cached in memory for 10 minutes.

These changes include code ported over from Read.Write.as, and thus
include some experimental features like filtering public posts by tags
and authors. These features aren't well-tested or complete.

Closes T554

This allows users to load a different configuration file instead of the
default config.ini. It works in combination with other configuration
actions, like --config and --create-config.

Ref T529

Ref T529

This changes what displays in the NodeInfo, and in the future might be
used for other things.

Minimal changes, definitely WIP, to resolve:

- how to support dualstack when not using localhost?
- net/http package uses string, mentions IP address instead of bind,
  need info.

This supports running the server on port 443, serving secure pages, with
automatic redirects from the insecure site. It also modifies the
configuration process to better guide users through configuring for
running behind a reverse proxy or as a standalone server.

This closes T537

- Database schema changes, removing obsolete custom domain-related code
- Missing user structs
- Setup verbiage changes
- Missing routes
- Missing error messages

This also includes a new Dev config options

Plus update copy / options / templates in the config process.

This adds a new --config flag and rearranges some config fields.

Includes new instance stats and the new option to show user stats, as
well.

This includes config changes, collections, posts, some post rendering
funcs, and actual database connection when the server starts up.