Add Gio::Permission

	* gio/giomm.h: Add giomm/permission.h.
	* gio/src/filelist.am: Add permission.hg.
	* gio/src/gio_signals.defs: Add allowed, can-acquire, and
	can-acquire properties.
	* gio/src/gio_vfuncs.defs: Add vfuncs.
	* gio/src/permission.[hg|ccg]: New files.
	* tools/extra_defs_gen/generate_defs_gio.cc: Add
	G_TYPE_PERMISSION.
	* See https://bugzilla.gnome.org/show_bug.cgi?id=732436
Add Gio::SimplePermission

	* gio/giomm.h: Add giomm/simplepermission.h.
	* gio/src/simplepermission.[hg|ccg]: New files.
	* gio/src/filelist.am: Add simplepermission.hg.
	* tools/extra_defs_gen/generate_defs_gio.cc: Add
	G_TYPE_SIMPLE_PERMISSION (although SimplePermission has no
	signals nor properties).
	* See https://bugzilla.gnome.org/show_bug.cgi?id=732436