infrun.c: Move non_stop_1 etc., higher up in file.

The "non_stop_1" global is out of place, mixed with the observer bits.
This moves all the non-stop user-interface-related bits together.

gdb/
2013-06-28  Pedro Alves  <palves@redhat.com>

	* infrun.c (non_stop, non_stop_1, set_non_stop, show_non_stop):
	Move higher up in file.
Move pagination_enabled declaration to a proper place.

Declare it close to other related declarations in utils.h, and remove
local extern declaration hack.

gdb/
2013-06-28  Pedro Alves  <palves@redhat.com>

	* infrun.c (set_observer_mode): Don't declare pagination_enabled
	here.
	* utils.h (pagination_enabled): Declare.