- crosses initializations in "cap_ximea.cpp" (which also contained some awfull "goto" instructions)
  - the "CMAKE_CL_64" variable is not initialized when using mingw

PR#1039 modified to be able to merge on branch 2.4

Allow to build samples via OpenCV binaries from distribution package
(find_package with OpenCV_DIR).

Looks like we don't actually use them; when creating precompiled headers
with Visual C++, a dummy .cpp is created at build time.

Now the HAVE_* macros are set in cvconfig.h. Most of them already were there,
but were nonfunctional.

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.

Also, removing explicit include path configuration,
since QT_USE_FILE takes care of that.

Fixed flann build with NEON;
Fixed Haming distance with NEON;
Honest cvRound for WinRT added;
cvRound test added;
Video IO with direct show disabled;

TIFF build was fixed;
Direct Show back-end was enabled;
More accurate guards implemented.

GPU module turned off;
TIFF support turned off;
Windows Managment and Video IO (VFW) turned off.

The video(4) driver provides a Video4Linux2 compatible API for
various video peripherals. This patch propagates HAVE_VIDEOIO if
the sys/videoio.h include file is found, which is the signature of
video(4).

This reverts commit 36135fc5.

Window-related functions is guarded from calls from application code.
Old implementations with "no-gui" exception are stell compiled and linked to OpenCV library for binary compatibility.