hdf5_ep

[svn-r18515] Bug:
PGI v10.2 in Red Storm Qual complained about the H5_IS_API macro with the
following message when -Mbounds is used:
   PGC-S-0053-Illegal use of void type 
The compiler did not like to treat the literal strings as arrays.
The -Mbounds option is used when --disable-production is used.

Solution:
Casted all the literal to (char *).

Tested:
h5committest passed.
Red Storm Qual passed with the fixed H5_IS_API macro though it has other
failures later. Will be fixed in another batch.