bug fixes to cpuEvalLimitKernel.cpp (use unsinge ivalence in the correct places)
bug fixes to cpuEvalLimitKernel.cpp (use unsinge ivalence in the correct places)

minor code cleanup

Note : there is still a resilient bug in the Gregory Boundary patch case

takahito-tejima/OpenSubdiv,c64kernal/OpenSubdiv,takahito-tejima/OpenSubdiv-exp,shengfuintel/OpenSubdiv,shengfuintel/OpenSubdiv,takahito-tejima/OpenSubdiv-exp,lookup1980/OpenSubdiv,c64kernal/OpenSubdiv,anshuarya/OpenSubdiv,jcowles/OpenSubdiv,c64kernal/OpenSubdiv,jcowles/OpenSubdiv,xldeveloper/OpenSubdiv,nyotis/OpenSubdiv,anshuarya/OpenSubdiv,takahito-tejima/OpenSubdiv,nyotis/OpenSubdiv,anshuarya/OpenSubdiv,takahito-tejima/OpenSubdiv,takahito-tejima/OpenSubdiv-exp,poljere/OpenSubdiv,takahito-tejima/OpenSubdiv-exp,poljere/OpenSubdiv,xldeveloper/OpenSubdiv,lookup1980/OpenSubdiv,poljere/OpenSubdiv,xldeveloper/OpenSubdiv,nyotis/OpenSubdiv,shengfuintel/OpenSubdiv,lookup1980/OpenSubdiv,jcowles/OpenSubdiv