Merge pull request #1088 from apacha:brisk_noDescriptors_fix
Deleted a bunch of unused configuration macros.
Removed a few more unused configuration macros.

I've left HAVE_LIBPTHREAD as a CMake variable, since TBB's build depends on it.

Some macros in internal.hpp depended on HAVE_ALLOCA_H, but they were, in turn,
unused, so I've just deleted them all.
Merge pull request #1077 from bitwangyaoyao:2.4_kmeans
Refactored detecting several Apple-related technologies.

Now the HAVE_* macros are set using cvconfig.h. Previously most
of them already were there, but were always undefined. One,
HAVE_COCOA, I had to add.

This also makes the CMake code more consistent; now, WITH_* variables
are always checked in cmake/*, while HAVE_* variables are checked in
modules/highgui/CMakeLists.txt.
Merge pull request #1 from Itseez/2.4

Add calculating integral image using IPP
Merge pull request #1102 from SpecLad:xls-updates
Merge pull request #1106 from pengx17:2.4_gftt_rename
Refactored image format library finding logic.

Now the HAVE_* macros are set in cvconfig.h. Most of them already were there,
but were nonfunctional.
Removed unused NEW_FFMPEG macro.
Removed the HAVE_LRINT macro, which is never set.
Removed unused PACKAGE_* macros.
Removed useless VERSION macro (and CMake variable)
Fixed VideoCapture::open() does not release previous capture sources (Bug #3150).

VideoCapture didn't call release method and just ignored the new capture sources.
OpenCV documentation:
  bool VideoCapture::open(const string& filename);
  bool VideoCapture::open(int device);

The methods first call VideoCapture::release() to close the already opened file or camera.
Sorted cvconfig.h.cmake in alphabetical order.
Fixed "FileStorage (minor) error in doc (Feature #3151)"

It was just a typo in the documentation.
Merge pull request #1111 from nikman-ru:fix_yamldoc
Merge pull request #1109 from nikman-ru:cap_reuse_24x
fix hog mismatch on cpu ocl
Merge pull request #1049 from pengx17:2.4_superres_ocl