indicator libraries: init at 12.10

The indicator libraries for GTK2 and GTK3.

The bindings for Mono do not work yet because of some issues with Perl in
gtk-sharp-2 and an Unhandled Exception caused by building with multiple cores:
https://aur.archlinux.org/packages/libindicate-sharp/#comment-290385

Some packages have TODOs for the indicator libraries,
since it is an optional dependency for most packages.
These packages have not been updated by this commit.