Move some static functions into the FarnebackOpticalFlow class as well,
so they can access these new class variables.
oclMat objects cannot be declared statically, because their destructor
depends on the statically defined __module variable from cl_context.cpp.
Since statically defined variables in separate compilation units have
an undefined destruction order there is always the possibility the
__module will be destructed before an oclMat object, which results
in a segfault.
Some of functions were enabled on Qualcomm S800 by changing grid size;
OpenCL kernel grid size unification for different platfroms;
Test pass rate improvements by inclreasing threshold;
Some tests were disabled for Android;
run.py was adopted for devices with brackets in in name.
2. Let Farneback to be the default optical flow method.
3. Fix a timing method bug for ocl path.
4. Remove useless finish operation in farneback
5. Refactor buffer usage.
