h5pget_class_f should return hid_t for classtype
Also removed all left over C comment artifacts /* and */ in the Fortran comments.
Tested: h5committest
and examples.
Platforms tested: Manual testing in place and using srcdir on jam, platypus, and emu with default and
PGI, Intel and new GNU compilers. ifort compiler was also tested with -i8 and -r8 flags
on jam. CMake tested on jam.