replace unhexify with hex2bin

replace unhexify with hex2bin

unhexify and hex2bin are identical, so this removes unhexify.  The
particular choice of which to keep was made on the basis of
parallelism with the earlier patch that removed hexify.

2014-02-12  Tom Tromey  <tromey@redhat.com>

	* common/rsp-low.h (unhexify): Don't declare.
	* common/rsp-low.c (unhexify): Remove.

2014-02-12  Tom Tromey  <tromey@redhat.com>

	* server.c (handle_query, handle_v_run): Use hex2bin, not
	unhexify.
	* tracepoint.c (cmd_qtdpsrc, cmd_qtdv, cmd_qtnotes): Likewise.