T-API: used vload/vstore

Perf results:
http://ocl.itseez.com/intel/export/perf/pr/2969/report/detail/20140711-125209-cbf63b0-acaf179_SHARK-BAY-HD4600_master_win64-vc11_regression_iGPU-HD4600.html?t0r3=0

check_regression=*OCL*
test_filter=fvdvdv
test_modules=core
build_examples=OFF