replace hexify with bin2hex

replace hexify with bin2hex

This removes hexify in favor of bin2hex.
The choice of which to keep was arbitrary.

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

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

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

	* remote-utils.c (look_up_one_symbol, monitor_output): Use
	bin2hex, not hexify.
	* tracepoint.c (cmd_qtstatus): Likewise.