perf tools: Separate out GTK codes to libperf-gtk.so

Separate out GTK codes to a shared object called libperf-gtk.so.  This
time only GTK codes are built with -fPIC and libperf remains as is.  Now
run GTK hist and annotation browser using libdl.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
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/1379053663-13706-1-git-send-email-namhyung@kernel.org


[ Fix it up wrt Ingo's tools/perf build speedups ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>