Version 4.19 Yay-sphinx-docs Release

This is just a quick release partly for posterity since after so long steamodd is finally getting documented properly but also because of the lobby ID property. Apparently it's going to be useful for people soon so might as well.

• Added lobbysteamid property to steam.user.profile (@miedzinski)
• (Finally) added more formal documentation. A sphinx build of these can be found on readthedocs (@ondrowan)