hdf5_ep

[svn-r11439] Purpose:
Bug fix

Description:
Using the -xarch=v9 flag to specify 64-bit compilation breaks C++ shared
libraries.
Disable shared C++ libraries if this flag is used.

Solution:
Instead of trying to disable compilers which recognize the -xarch flag,
grep for it in CXX, CXXFLAGS, etc.

Platforms tested:
modi4, shanti, sleipnir

Misc. update:
Update to RELEASE and build instructions will be forthcoming once
shared Fortran/C++ libraries are regularly passing the Daily Tests.