hdf5doc

Purpose:
    Clarify that the length of names of objects in groups is not limited.
Description:
    H5Gcreate, H5Dcreate, H5Tcommit
        Added a note in each of these function descriptions that the
        length of the created object's name is unlimited.
        Included note that this is true for all objects in a group.
    Additional code cleanup in H5Gcreate and copy edit in H5Tcommit.
Platforms tested: 
    Safari