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.