GNOME3 app menu integration

Piggy backing on some of the Unity LibreOffice Application Menubar work and the existing support for the MacOSX equivalent. I finally got around to adding a GNOME3 application menu to LibreOffice

Converting LibreOffice dialogs to .ui format, 300 conversions milestone

We’ve now reached 300 dialogs and tabpages converted from LibreOffice’s classic fixed widget size and position .src format to the GtkBuilder .ui format.
So, by my earlier estimates this puts us at about the half-way conversion mark.
The How to conversion guide is still relevant, and help is always appreciated.
In terms of writer, the major dialogs which are not completely converted are the frame and “table of contents” ones which are only partially converted, while there’s no conversion of any of the hyperlink dialog pages yet. While the paragraph and character dialogs are now fully converted over.