vchoi_fork

[svn-r17182] In my last round of checkin (r17177), I forgot to clean up some code.  I'm checking in
the fix now.  Another minor fix - The way that H5Tset_size checks whether the datatype 
is a string wasn't correct.  I changed it to use the macro H5T_IS_STRING.

Tested on jam, smirom, and linew.