tomahawk: 0.8.3 -> 0.8.4

From the Changelog:
  * Fixed drag & drop issues on sidebar.
  * Fixed starting Tomahawk with a filename as parameter.
  * Update column view when collection changes.
  * (Linux) Don't crash on environments with invalid locales.

Signed-off-by: devhell <"^"@regexmail.net>
Closes: #9858
Tested-by: aszlig <aszlig@redmoonstudios.org>
Tested-by: David Kleuker <post@davidak.de>