- IPP is disabled by default when compiler is mingw (couldn't make it
work)
- fixed some warnings
- fixed some `__GNUC__` version checks (for correctness and convenience)
- removed UTF-8 BOM from hough.cpp (fixes #5253)

1. someMatrix.data -> someMatrix.prt()
2. someMatrix.data + someMatrix.step * lineIndex -> someMatrix.ptr( lineIndex )
3. (SomeType*) someMatrix.data -> someMatrix.ptr<SomeType>()
4. someMatrix.data -> !someMatrix.empty() ( or !someMatrix.data -> someMatrix.empty() ) in logical expressions

Conflicts:
	modules/core/include/opencv2/core/cuda.hpp
	modules/cudacodec/src/thread.cpp
	modules/cudacodec/src/thread.hpp
	modules/superres/perf/perf_superres.cpp
	modules/superres/src/btv_l1_cuda.cpp
	modules/superres/src/optical_flow.cpp
	modules/videostab/src/global_motion.cpp
	modules/videostab/src/inpainting.cpp
	samples/cpp/stitching_detailed.cpp
	samples/cpp/videostab.cpp
	samples/gpu/stereo_multi.cpp

libpng 1.5+ recommends a call to png_set_interlace_handling() if you use
png_read_update_info and png_read_image. It will generate a warning
without it.

Correct reading PNG color type palette with or without alpha imread flags -1 or 1
Better not using pnginfo.h, using png_get_tRNS instead

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.

Made all STL usages explicit to be able automatically find all usages of
particular class or function.

put template Distance classes back to features2d, since they are used in GPU; fixed OpenCV build with Xcode 2.3 (which includes new libpng)

updated 3rd party libs: CLapack 3.1.1.1 => 3.2.1, zlib 1.2.3 => 1.2.5, libpng 1.2.x => 1.4.3, libtiff 3.7.x => 3.9.4. fixed many 64-bit related VS2010 warnings