opencv: Update to 2.4.10

Also
- fixed OpenCV_INSTALL_PATH in cmake use-script. This fix is included into the updated mingw-w64-cmake.patch;
- enabled OCL module. OpenCL headers ship with OpenCV sources and needed only at build time. At runtime opencl.dll is loaded dynamically (if available). Hence enabling this module does not restricts usage of the library;
- enabled VIZ module. This requires the fixed VTK use-scrpts from PR #239 .