IPP can be switched on and off on runtime;

Optional implementation collector was added (switched off by default in CMake). Gathers data of implementation used in functions and report this info through performance TS;

TS modifications for implementations control;

removed optim module; moved its functionality to core and photo modules; moved drawing functions from core to imgproc. Removed FilterEngine etc. from public API

1. someMatrix.data -> someMatrix.prt()
2. someMatrix.data + someMatrix.step * lineIndex -> someMatrix.ptr( lineIndex )
3. (SomeType*) someMatrix.data -> someMatrix.ptr<SomeType>()
4. someMatrix.data -> !someMatrix.empty() ( or !someMatrix.data -> someMatrix.empty() ) in logical expressions

When using perspectiveTransform in rather complicated settings, it would be easier for developers to have two separate assertions for each part of the boolean expression in order to pinpoint problems more efficiently. In my case I am struggling in Python2.7 with finding out whether scn+1 == m.cols or the depth == CV_32F || depth == CV_64F is making a problem, which is kind of hard.

initialization time.