PR python/17698 - add Breakpoint.pending

PR python/17698 - add Breakpoint.pending

This patch adds a "pending" attribute to gdb.Breakpoint.

Built and regtested on x86-64 Fedora 23.

2016-07-13  Tom Tromey  <tom@tromey.com>

	PR python/17698:
	* NEWS: Update.
	* python/py-breakpoint.c (bppy_get_pending): New function.
	(breakpoint_object_getset): Add entry for "pending".
	* breakpoint.h (pending_breakpoint_p): Declare.
	* breakpoint.c (pending_breakpoint_p): New function.

2016-07-13  Tom Tromey  <tom@tromey.com>

	PR python/17698:
	* python.texi (Breakpoints In Python): Document
	Breakpoint.pending.

2016-07-13  Tom Tromey  <tom@tromey.com>

	PR python/17698:
	* gdb.python/py-breakpoint.exp (test_bkpt_basic): Add "pending"
	test.
	(test_watchpoints): Likewise.
	(test_bkpt_pending): New proc.