[Qgis-developer] Plugin reorganization (again)

[Alexander Bruy]

Hi all,

finally I push all changes to master. This include:
 - new methods to add/remove plugins from Raster menu
   addPluginToRasterMenu(QString, QAction)
   removePluginRasterMenu(QString, QAction)
 - new methods to add/remove plugin buttons from Raster toolbar
   addRasterToolBarIcon(QAction)
   removeRasterToolBarIcon(QAction)
 - new Vector menu and toolbar
 - new methods to add/remove plugins from Vector menu
   addPluginToVectorMenu(QString, QAction)
   removePluginVectorMenu(QString, QAction)
 - new methods to add/remove plugin buttons from Vector toolbar
   addVectorToolBarIcon(QAction)
   removeVectorToolBarIcon(QAction)
 - new Database toolbar
 - new methods to add/remove plugin buttons from Database toolbar
   addDatabaseToolBarIcon(QAction)
   removeDatabaseToolBarIcon(QAction)
 - core plugins reorganized and moved under appropriate menus/toolbars.
   There are some issues with plugins that match to several categories, e.g.
   Zonal Statistics plugin. Also some plugins still remain in Plugins menu.
 - introduced new plugin metadata entry "category". This entry currently used
   only in informational purposes to inform user where he should look
for plugin.
   Placing plugin under appropriate menu remains developer task and can be done
   with new methods described above. If no category specified Python plugin will
   get default one - "Plugins".
   Also updated QgsPlugin class to handle this new metadata, so C++ plugins
   must be updated and recompiled (looks like an API break)
 - updated Plugin Manager to display hint based on "category" metadata

Hope, I didn't break anything.

-- 
Alexander Bruy