This patch effectively does the following:

1) Refactors the KisPaintDevice so that the behavior of most of
   the methods is switchable with a strategy. There are two strategies
   available: KisPaintDeviceStrategy and KisPaintDeviceWrappedStrategy.

2) The choice of Wrapped/Unwrapped mode is defined by the KisDefaultBounds
   object, which is accessible from all the paint devices of the image.

3) Implements wrapped versions of hline, vline, rect and random accessor
   iterators. Construction of different iterators is done by means of
   switching strategies.

4) The basic maths of the wrapping is done by a special object named
   KisWrappedRect.