[Vala] Error compiling with gedit module

[Damien Radtke <damienradtke gmail com>]

I can't get the gmodule to work correctly. pkg-config --print-provides
gedit-2.20 returns 2.30.4, so I know it's installed. Valac succeeds, but
then it quickly runs into a gcc error along the lines of "undefined
reference to `gedit_document_new'".

Any idea why this wouldn't be working?