Add more error API verbosity
Add more error API verbosity

We now report errors when the return code is returned via a integer
argument to function, even if that pointer is null.

bitfusionio/Oclgrind,mpflanzer/Oclgrind,bitfusionio/Oclgrind,bitfusionio/Oclgrind,surround-io/oclgrind,bitfusionio/Oclgrind,mpflanzer/Oclgrind,surround-io/oclgrind,surround-io/oclgrind,mpflanzer/Oclgrind,mpflanzer/Oclgrind,surround-io/oclgrind