instead of linking to posts only on a user's blog.

Ref T681

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

i.e. current tag a user is browsing, when they are.

Ref T681

This adds a new editor template that strips away most of the
customization features in the default editor and includes only:

- publishing
- editing
- viewing word count

It also restricts publishing to a user's first collection, so it's
optimized for instances that only allow users to have a single
collection and don't use Drafts.

Ref T680 T677

This shows About, Reader, Log out links on backend user pages when
logged in. It also adds "New post" buttons on the backend pages and
blogs.

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

Support <audio> element

Automatic certificates from Let's Encrypt

Resolves T542

Fix go-sitemap-generator overriding GOMAXPROCs

changed to use stm.URL for imgs for readability
fixed error in append statement
reordered import statements

This whitelists the HTML5 <audio> element and adds some basic style to
make it look nice.

Don't consider post unpublished when title exists

This adds a new "Secure (port 443), auto certificate" option to the "Web
server mode" prompt when running `writefreely --config`. When chosen,
it'll set `autocert` to `true` and set the path for certs and keys to
`certs`.

Ref T542

This fixes certificate validation, while keeping HTTP -> HTTPS
redirection.

Ref T542

Previously, this would pass in the instance's full (and invalid) URL.
Now it passes only the host name.

Ref T542

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 upgrades the library to v2, which lets you specify that GOMAXPROCs
should always be the max number of CPUs -- and then sets it to that.

One side effect of this is that images are no longer listed in sitemaps.
I'm somehow at a loss on how to build and append the images array we
need, with the library's latest changes.

Fixes #86

Prevent transliterated slugs exceeding length limit

Previously, you could create a post with a title but no body, e.g. by
publishing via email. This would still show the post on a blog, but
would give a 410 Gone page when trying to access the page.

This issue originally reported on the forum:
https://discuss.write.as/t/removing-post-unpublished-by-author-post/725

Transliteration during slug generation can cause slugs to exceed their
80-character limit. This fixes that by making a second truncation pass
on the slug during generation.

Originally reported on the forum:
https://discuss.write.as/t/title-convert-to-url-function-bug-under-chinese/723

This closes #135

This makes it easy to build WF for ARMv7, e.g. the Raspberry Pi.

part of #135

instead of *App

instead of *App

instead of "Anonymous".

This was still a relic of Write.as. Now it has the same icon as the
WriteFreely editor.

Private instances

Resolves T576

Customize landing page

Resolves T565

Previously, we just included the value of `ul`, which is a func. This
now calls `ul()` and logs that value.

Shorter config process

This runs `go fmt` on changed files and moves around some blank lines.

Closes #132

This makes the naming scheme more consistent with other funcs.

Ref T565

This enables admins to customize their landing / home page via the Admin
dashboard -- including the text at the top of the page and the section
below it. It keeps the current default text, falling back to it if the
user hasn't overwritten it.

Ref T565

This supports admins previewing changes to the landing page.

Ref T565

Construct version from annotated tags only

Fixes issue 125

Fix #124 according to the snippet by @mrvdb

do anything useful (see https://github.com/writeas/writefreely/pull/128#issuecomment-506207107)