* core:ppc Fix java CoreTest/testMahalanobis

* core:ppc Fix warning unused variable on clang

* Introduces error throw for line drawn with THICKNESS=0

- disabled xfeature2d dependency for java wrappers
- fixed java wrappers build after cmake rerun
- disabled opencv_ml tests temporarily
- fixed Imgproc usage in java tests

small matrix becomes the same after shuffling

* Drop some low level API
* Remove outdated overloads
* Utilize Input/OutputArray

moving inpaintTest() to 'photo';
hiding 'Point*' arg in Java signature of Core.checkRange().

updated links in cheatsheet
renamed directory for Mat tutorial 
changed links from willow docs to opencv.itseez.com, from Trac to current Redmine

* fixed manually ported classes;
* added vector<vector<Point>> support;
* changed argument types for 3 functions;
* finished tests for org.opencv.core.Core class.

Java API: fixed problems in video and ml modules; generated test stubs for all exported functions (now we have 1701 tests).

Testing: 1079/0/584