* fix for feature2d java wrappers as described in this post: http://answers.opencv.org/question/101675/surfsift-java-wrapper-for-opencv-3xosx-1011/

* fix for feature2d java wrappers as described in this post: http://answers.opencv.org/question/101675/surfsift-java-wrapper-for-opencv-3xosx-1011/

* rollback of one change as requested (similar change already merged)

* normHamming done with AVX 2 intrinsics.

* fixed compiling AVX2-optimized norm hamming with MSVC

make sure that the empty mat is copied to UMat properly - i.e. UMat becomes empty. Before the patch such copy operation crashed

1) fix include directories
2) don't use PCH for source file with custom COMPILE_FLAGS

  * add v_abs for universal intrinsic
  * add test of v_abs in test_intrin
  * fix compile error on gcc
  * fix bool OR operation