[Win32-Installer] Force .NET 4.0/4.5 on Windows even if built with 2.0/3.5
[Build] Bumped version to 0.8.12
[Build] Updated bug tracker URL to smuxi.im
[IRC] Support non-RFC channel privileges.

Add support for non-RFC channel privilege modes such as owner, channel admin
and halfop to the IRC engine and the GNOME frontend.