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

They're not listed in the documentation for the FindZLIB module,
so we shouldn't use them unless necessary.

for libpng added.

On Android memory is not guaranted to be aligned and applications often crash with BUSERROR

* Fixed zlib search.
* Fixed compiler/linker flags caching bug.
* Fixed OpenCVConfig.cmake generation (currently tested only on Unix).

HAVE_CONFIG_H -> HAVE_CVCONFIG_H

[~] fixed warning in featuers2d under windows (can't generate assignment operator)

Basically just adding lines at top of CMakeLists that alter behavior if ANDROID is set to
true.

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