perf ui/gtk: Implement basic GTK2 annotation browser

Basic implementation of perf annotate on GTK2.  Currently only
shows first symbol.  Add a new --gtk option to use it.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1360227734-375-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-annotate.txt

@@ -61,11 +61,13 @@ OPTIONS
 
 --stdio:: Use the stdio interface.
 
---tui:: Use the TUI interface Use of --tui requires a tty, if one is not
+--tui:: Use the TUI interface. Use of --tui requires a tty, if one is not
 	present, as when piping to other commands, the stdio interface is
 	used. This interfaces starts by centering on the line with more
 	samples, TAB/UNTAB cycles through the lines with more samples.
 
+--gtk:: Use the GTK interface.
+
 -C::
 --cpu:: Only report samples for the list of CPUs provided. Multiple CPUs can
 	be provided as a comma-separated list with no space: 0,1. Ranges of