Into the Pandemonium

Improvements since v1:

* added Metal-Archives as a source for the releases. This gives us a lot
  of results, so even the daily posts can become overwhelming (see
  improvements about post chunking).
* fetch command can accept year and month options to restrict the period
  for which to try to load releases. This doesn't work on the Wikipedia
  source, which has the whole year on the same page.
* this is accompanied by a --date flag which has replaced the --year
  one.
* the post command now does some more advanced chunking of the releases in
  order to make sure the message fits in the 500 character limit of
  Mastodon.
* the posts are now in a thread so they can be kept track of more
  easily.
* the posts now include the tags that the source gives for each release.
  This list can get quite big for some, so it will need some tuning in
  the near future, ie, stripping some of the more obscure ones.
* small improvements to authorizing the client if there is not a token
  provided.
* started the work to allow for the auth command to upload avatar/header
  images and, maybe, update the description/name of the account used.