Add pretty-printer for MPX bnd registers.

Add pretty-printer for MPX bnd registers.

Boundary length is simpler implemented by means of a pretty
printer. This simplifies users life when examining a bound register.

Changelog:
2013-11-20  Walfred Tedeschi  <walfred.tedeschi@intel.com>

	* python/lib/gdb/command/bound_register.py: New file.
	* gdb/data-directory/Makefile.in: copy bond_register.py to the right path to
	be initialized at gdb startup.
testsuite/
	* gdb.python/py-pp-maint.exp: Consider new pretty-print added for registers.

Change-Id: Id4f39845e5ece56c370a1fd4343648909f08b731
Signed-off-by: Walfred Tedeschi <walfred.tedeschi@intel.com>
Conflicts:

	gdb/ChangeLog