hdf5_msb

[svn-r12341] 
Purpose: Maintenance

Description: dtypes.c compilation failed with gcc 4.1 due to the
             missing prototype of the opaque_funcs function.
             Failure was reported by a user who tried to build
             hdf5-1.8.0-alpha2.
             I reproduced the failure on sleipnir with gcc41
             compiler.

Solution: Added prototype definition.

Platforms tested: sleipnir with gcc41, heping and copper

Misc. update: