perf_counter tools: Add color terminal output support

Add Git's color printing library to util/color.[ch].

Add it to perf report, with a trivial example to print high-overhead
entries in red, low-overhead entries in green.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/Documentation/perf_counter/Makefile b/Documentation/perf_counter/Makefile
index 414399c..c9ec458 100644
--- a/Documentation/perf_counter/Makefile
+++ b/Documentation/perf_counter/Makefile
@@ -298,6 +298,7 @@
 LIB_H += util/run-command.h
 LIB_H += util/sigchain.h
 LIB_H += util/symbol.h
+LIB_H += util/color.h
 
 LIB_OBJS += util/abspath.o
 LIB_OBJS += util/alias.o
@@ -319,6 +320,7 @@
 LIB_OBJS += util/wrapper.o
 LIB_OBJS += util/sigchain.o
 LIB_OBJS += util/symbol.o
+LIB_OBJS += util/color.o
 LIB_OBJS += util/pager.o
 
 BUILTIN_OBJS += builtin-help.o