Import button crash for abr

[LukasT.dev@gmail.com]

Hi,

there is crash when you add abr brush to the brush chooser with Import button 
( It has + icon ;) ). The problem is that importResource calls createResource.
The architecture is done for one file - one resource. But abr brush consists of 
N brushes and we handle single bitmap as resource.

createResource returns KisBrush * in kis_brush_server.cpp
There is also method createResources but it is not called when import is used.
So when we createResource for abr brush, it is not handled, just gih and gbr 
are.

Can you help me to fix it?
I suppose Sven would know nicer solution :)