ResourceEditor: Fix saving of multiple prefixes with different languages

Also fix the quadratic peformance.

Change-Id: I7287bd23438b4b018a4bf8ee891a4532ec9b4ba8
Reviewed-by: hjk <hjk121@nokiamail.com>
ResourceEditor: Remove even more dead code

Change-Id: I5b2f01b5cdf512f2cc125481f0db999d111c3a54
Reviewed-by: hjk <hjk121@nokiamail.com>
ProjectExplorerPlugin: Treat VirtualFolders as Foldes for context menus

Change-Id: I33556b0296a85c8321d785dbe819fcac98d0afb1
Reviewed-by: hjk <hjk121@nokiamail.com>
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
ProjectNodes: Move vcsTopic to where it belongs

It's a nonsensical operation on anything but ProjectNodes

Change-Id: Id02682e6dde99c5a08362dac0f6286282cfc15b6
Reviewed-by: hjk <hjk121@nokiamail.com>
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>