vstudio: remove dependency to msvcp dll

using the /MT code flag, binary is only 7K bigger and remove
the requirement of a 500KB dll...
cuda_mul: remove dev. printf (vfprintf error)
whirlpool: restore full speed on the 750 Ti
m7: cleanup, add CUDA_SAFE for m7 (prevent bug on double launch)

added CUDA_SAFE error check define in cuda_helper.h