fixed NPP error constants usage
fixed constructors for functional objects (added __host__ modifier)
rewrite core/cuda/vec_math.hpp file

old version isn't compiled with CUDA 5.5
new version doesn't depend on functional.hpp
fixed BroxOpticalFlow regression test

the output of BroxOpticalFlow differs a bit in CUDA 5.5
fixed BoxFilter sanity test (different rounding results)
fixed BroxOpticalFlow sanity test (increase epsilon value)
Merge pull request #964 from jet47:cuda-5.5-support