hdf5_ep

[svn-r18961] Purpose:
  Fixed Windows compile error. Renamed to use 'gid1' and 'gid2' instead of 
  'grp1' and 'grp2'. 

Description:
  This is related SVN r18946. 
  There is variable name confliction with 'grp1' ~ 'grp9' in Windows system. 
  It occurs if H5private.h is included in the code.