cmake: restore find_package() for build directory
cmake: add opencv_java into list of exported targets (fix for android)
cmake: fix linker deps for CUDA
Fix running Java tests with run.py on everything other than Windows.

Previously, run.py would assume that the opencv_java library is in the
same directory as the tests, which is only true on Windows.

The library path depends on the build configuration, which may not be
known until the actual build (e.g. with the Visual Studio generators),
so it can't be stored in the CMake cache for run.py to read. I didn't
want to hardcode into run.py where the library is on each platform,
either. So that's why I used the current scheme with the properties
file. It also makes running the tests without run.py a little easier.
ocl: rewrite CvtColor tests, added roi support
Merge pull request #1634 from alalek:cmake_fix_cuda_linker_deps
Merge pull request #1635 from alalek:cmake_fix_export_java
Merge pull request #1632 from alalek:cmake_find_package_build_dir
Merge pull request #1613 from alalek:ocl_cvtcolor
Merge pull request #1637 from SpecLad:run-py-java-fix