hdf5_der

[svn-r17141] Description:
	Change name of public 'H5D_CHUNK_BTREE' symbol (indicating the type
of index used for locating chunks) to 'H5D_CHUNK_IDX_BTREE', putting old name
in "deprecated symbols" section.  This will make adding new indices (like
extensible and fixed arrays) more nicely named.

Tested on:
	FreeBSD/32 6.3 (duty)
	(h5commitest not required on branch)