Dmitry Kazakov authored Dec 17, 2013 and Halla Rempt committed Dec 18, 2013

Now when the source image is changed we use an iterational algorithm
which is usually applied to a SeqLock problem:

1) Save the size and lastModified tag of the image
2) Copy the image to the temporary directory
3) Check whether the image has changed during the copy operation
4) If everything is ok load the image from a temporary copy. If not,
   restart.

BUG:325686

Conflicts:
	krita/ui/kis_file_layer.cpp