bump version to match revision. add unittest

BUG=none
TEST=none
Review URL: https://webrtc-codereview.appspot.com/369016

git-svn-id: http://libyuv.googlecode.com/svn/trunk@159 16f28f9a-4ce2-e073-06de-1de4eb20be90

README.chromium

 Name: libyuv
 URL: http://code.google.com/p/libyuv/
-Version: 154
+Version: 159
 License: BSD
 License File: LICENSE
 

include/libyuv/version.h

@@ -16,7 +16,7 @@ namespace libyuv {
 extern "C" {
 #endif
 
-#define LIBYUV_VERSION 154
+#define LIBYUV_VERSION 159
 
 #ifdef __cplusplus
 }  // extern "C"

unit_test/cpu_test.cc

@@ -15,6 +15,7 @@
 
 #include "libyuv/basic_types.h"
 #include "libyuv/cpu_id.h"
+#include "libyuv/version.h"
 
 namespace libyuv {
 
@@ -25,4 +26,8 @@ TEST_F(libyuvTest, TestLinuxNeon) {
   EXPECT_NE(kCpuHasNEON,ArmCpuCaps("testdata/tegra3.txt"));
 }
 
+TEST_F(libyuvTest, TestVersion) {
+  EXPECT_GE(159,LIBYUV_VERSION);
+}
+
 }  // namespace libyuv