Linker dependencies are transitive for non-private

- removed OpenCV_LIB_DIR* vars (they are broken and not required anymore)
- OpenCVConfig.cmake doesn't contain ANDROID/CUDA code if there is no such support
- removed OpenCV2_INCLUDE_DIRS_CONFIGCMAKE, merged into OpenCV_INCLUDE_DIRS_CONFIGCMAKE
- fix hard-coded relative paths for OpenCV_INSTALL_PATH
- removed OpenCV_TBB_ARCH
- switch OpenCVConfig.cmake into 2-level mode for Android SDK

Some CMake 3.x (2.8.12.2 is fine) provides broken build configurations
with following build error message:
    ld: fatal error: -soname: must take a non-empty argument

Linker command line sample contains this:
"-shared -Wl,-soname, -o"

combinations of translation, rotation, and uniform scaling equals four degrees of freedom

Correcting return type from videoDevice::findType to be int thus allowing detection of failed device init request

  * loosen the threshold only under aarch64
  * fix #6610