4 digit library version numeration implemented in OpenCV Manager

Code refactoring done.
OpenCV library version type changed to int.
Some UI labels updated.
OpenCV Manager verison incremented.
Consistently use 4-digit library version
Add opencv_cheatsheet.pdf to documentation build and silence Latex output
Merge pull request #309 from asmorkalov:android_manager_4number_version
Merge pull request #310 from taka-no-me:4digit_version
Merge pull request #312 from taka-no-me:cheatsheet