Vendor dependencies for writeas-cli

Use go modules to vendor the dependencies we need for the writeas-cli build.

Add password flag for authentication

Closes T692

This is unavailable at the moment.

When logging in we had a cast that was made redundant, since
`pass` is now a string.

Fixes up the interactive authorization workflow so that
pass is reassigned properly.

For T692

For T692

WriteFreely CLI v1.0

for writeas-cli and wf-cli.

add accounts command

Resolves T672

This replicates behavior elsewhere, where we don't output anything if
there is no information to show. Instead, the "no accounts" message will
only show if the user supplies a -v / --verbose flag.

- Remove description
- Fix usage (it only shows drafts)
- Remove --md flag (Markdown is always rendered on draft posts)
- Fix --verbose description

this adds a new sub command accounts, which will list all currently
authenticated user accounts grouped by hostname

This isn't needed / used in WriteFreely.

Support any writefreely instance

Resolves T586 T594 T595 T635

this adds a new sub command accounts, which will list all currently
authenticated user accounts grouped by hostname

this changes DoUpdate and DoDelete to load the user and set the access
token in the client when no edit token is provided.

this adds a check for any logged in users on any host when neither the
user or host flag are passed and not default pair is configured

if the user flag is provided auth should attempt to authenticate with
that user.

previously when the user flag was provided, the function would still try
to get a user from config. flag should take precedence

this adds a check for configured defaults during the command pre check
when authentication is required. using the values found if both are
present and only if both flags are ommitted.

now that the scheme is not required in the configuration file, we can
assume the configured value is correct. as with other uses, the
configured value is only used when noth host and user are present.

if both a user and host are configured, the command auth should assume
that user and host when none specified

this updates newClient to prepend the scheme https to the default host
found in the global config, and only use said host when both the user
and host are configured

by needed: when host flag was supplied, matches that configured and a
user is set in config as well. they should be a pair.

this uses the usersLoggedIn helper to check for already logged in users,
selecting the single user when only one present and returning and error
when multiple are logged in.

this function checks the host based path for any logged in users and
returns the number or users, a list of usernames and an error if any

for use outside of package

to start on a fix for user actions when logged in with one user on a
given host with the wf binary, a user should now only be loaded by the
caller of newClient.

newClient no longer takes a bool for authRequired, all calls
updated to new signature and load the user where required.

On logout, this deletes host / user directories if they're empty.

Ref T586