Improved Android SDK search, fixed some bugs.

moving the rest of inpaint() to the 'photo' module, temporary disabling Java test for it, adding 'photo' to Java API

More granular build of Java API: it is now possible to build Java wrappers only for the subset of OpenCV modules

Better variant of OpenCVConfig.cmake generation; several smaller changes in the options section and Android build scripts

 [~] Automatically tracked dependencies between modules
 [+] Support for optional module dependencies
 [+] Options to choose modules to build
 [~] Removed hardcoded modules lists from OpenCVConfig.cmake, opencv.pc and OpenCV.mk
 [+] Added COMPONENTS support for FIND_PACKAGE(OpenCV)
 [~] haartraining and traincascade are moved outside of modules folder since they aren't the modules

Added option INSTALL_ANDROID_EXAMPLES (default off); Added option for choosing SDK platform for Android tests and samples.

Turned off android camera and java wrappers for low Android API levels (android-8 is required for these components)

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

Added video.hpp header (for convenience with other modules); added option to specify list of headers for Java API generator