[gedit-list] Deprecated API for gedit plugins removed for 3.12

[Sébastien Wilmet <swilmet gnome org>]

Hi,

gedit has a new design:
http://blogs.gnome.org/nacho/2014/01/15/gedit-has-a-new-face/

With this new design, there is an API break for plugins for menu items.

And since there is already an API break, I've removed the deprecated API 
as well. This was only for the search and replace functions in 
GeditDocument. You should use the GtkSourceSearchContext API in the 
GtkSourceView library instead. Normally few plugins are affected. Only 
one official plugin was using this API, and has been ported during the 
last development cycle.

Cheers,
Sébastien