Redefine CPU_xx constants in cv::namespace

This makes them visible from the python bindings
Fix mouse handling in python demos
GSoC Python Tutorials
GSoC Python Tutorials

removed white spaces

removed blank lines at EOF

removed duplicate labels
erGrouping now uses a classifier for group validation instead of a set of heuristical ifos.
Updated documentation and sample to use the new function API
Merge pull request #1520 from lluisgomez:scene_text_erGrouping_classifier
Merge pull request #1488 from abidrahmank:py_tutorials
Merge pull request #1477 from nzjrs:python-gethardwaresupport
Merge pull request #1429 from nzjrs:fix-sketcher