hdf5_ep

[svn-r10587] Purpose:
Minor feature

Description:
If a user configures without C++ or Fortran, 'make' will not recurse into
c++ or fortran directories.  However, if the user cd's into these
directories and 'makes,' the Makefiles will attempt to build interfaces
that have not been configured, usually failing.
In an unrelated but minor change, src/H5detect should be compiled with
the -g flag to disable compiler optimizations since it is only
executed once.

Solution:
Make it harder for users to try to compile interfaces that have not been
configured by making c++, fortran, and hl directories not recurse into
their subdirectories unless they have been configured.
Thus, 'make' in /fortran/src will break if Fortran has not been configured,
but 'make' in /fortran will not break.

Platforms tested:
mir, modi4, copper

Misc. update: