The interactive parts become an Interactor, and the visual changes in
the last iteration are mostly reverted. The handles are simple rect
items again, and now they are always visible to improve the
discoverability of this feature.

This commit also solves a long-standing bug: Sometimes, when enlarging
the scene rect beyond the view's boundaries, its size increased much
more than wanted. This is now gone.

svn path=/trunk/KDE/kdegames/palapeli/; revision=1111398