Add VP9 codec to VCM and vie_auto_test.

Include VP9 tests in videoprocessor_integrationtests.
Include end-to-end send/receiveVP9 test.

This is the same patch as https://code.google.com/p/webrtc/source/detail?r=7422, which was reverted when rolled into chrome (due to bss size increase). Relanding this again as we now have the clear to get this in:
see https://code.google.com/p/webrtc/issues/detail?id=3932

R=kjellander@webrtc.org, mflodman@webrtc.org, stefan@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/31829004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7588 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/modules/video_coding/main/interface/video_coding_defines.h

@@ -39,6 +39,7 @@ namespace webrtc {
 #define VCM_RED_PAYLOAD_TYPE        96
 #define VCM_ULPFEC_PAYLOAD_TYPE     97
 #define VCM_VP8_PAYLOAD_TYPE       100
+#define VCM_VP9_PAYLOAD_TYPE       101
 #define VCM_I420_PAYLOAD_TYPE      124
 #define VCM_H264_PAYLOAD_TYPE      127