plugins.hitbox: Add support for HLS videos.
docs: Add Slackware package to install page.
stream: Add some generic stream options.

These are generic options used by streams not covered by other options,
such as stream protocols specific to plugins, e.g. UStream.
Update CHANGELOG.rst.
docs: Add Ubuntu Utopic to install page.
docs: Add some info about multi-threaded streaming.
Added GoodGame.ru portal plugin
plugins.goodgame: Minor tweaks.

Also check if stream is available before adding it.
Merge pull request #466 from eltiren/develop

Added GoodGame.ru portal plugin
docs: Update plugin matrix.
Update CHANGELOG.rst.
travis: Remove pypy.
plugin.gaminglive: basic support for gaming live
plugin.gaminglive: accept new alpha.gaminglive.tv url
plugins.gaminglive: Make use of the validation API.

Also convert line endings from dos to unix.
Update CHANGELOG.rst.
docs: Update plugin matrix.
Update AUTHORS.
Merge pull request #468 from chhe/gaming-live

Added plugin for gaminglive.tv.