Fix memory leaks in NS version.

* src/macfont.m (CG_SET_FILL_COLOR_WITH_GC_FOREGROUND)
(CG_SET_FILL_COLOR_WITH_GC_BACKGROUND)
(CG_SET_STROKE_COLOR_WITH_GC_FOREGROUND): Fix memory leak.

* src/nsfns.m (Fx_create_frame): Fix memory leak.

* src/nsterm.h (EmacsApp): Add shouldKeepRunning and isFirst for
OSX >= 10.9.

* src/nsterm.m (init, run, stop:): New methods in EmacsApp for
OSX >= 10.9 to prevent memory leak of GCD dispatch source.

Conflicts:
	src/ChangeLog
* nsfns.m (Fns_convert_utf8_nfd_to_nfc): Check input for valid UTF-8
or throw error.

Conflicts:
	src/ChangeLog
toolbar: fix separator insertion bug
declare addDisplayItemSpacerWithIdx:tag:key to remove compiler warning
Declare window_header_line_inhibited_p to remove compiler warning.