hdf5_ep

[svn-r25652] Bug fix: HDFFV-8933

Description:
Mac has changed to use the clang/clang++ compilers but compiler settings for production, debug and profile
were not setup.

Solution:
Setup default values for PROD_CFLAGS, PROD_CPPFLAGS, DEBUG_CFLAGS, DEBUG_CPPFLAGS.
PROFILE_CFLAGS and PROFILE_CPPFLAGS were set too but clang does not -pg or such for
profiling. Need to fix it later.

Tested: duck, swallow, and quail using --enable-production.