command line option '-Wsign-promo' is valid for C++/ObjC++ but not for C [enabled by default]

Fixed issues: #2737 #2848

- added CMake toolchain file
- added WITH_NVCUVID flag

 - exclude system paths from library search paths
 - remove hardcoded paths to compiler
 - enable compiling with 3d-parties
 - enable build as shared libraries

* added CMake toolchain file
* added WITH_NVCUVID flag

disabled -Wunused-but-set-variable because of multiple warnings during building nvcc auto generated files (GCC 4.6)

Added check for CUDA toolkit version ( older can't compile Kepler )
........

 [~] 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