Add ToString() to VideoSendStream::Config.

Adds ToString() to subsequent parts as well as a common.gyp to define
ToString() methods for config.h. VideoStream is also moved to config.h.

BUG=3171
R=mflodman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/11329004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@6170 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/common.gyp b/common.gyp
new file mode 100644
index 0000000..b6b6354
--- /dev/null
+++ b/common.gyp
@@ -0,0 +1,20 @@
+# Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
+#
+# Use of this source code is governed by a BSD-style license
+# that can be found in the LICENSE file in the root of the source
+# tree. An additional intellectual property rights grant can be found
+# in the file PATENTS.  All contributing project authors may
+# be found in the AUTHORS file in the root of the source tree.
+{
+  'includes': ['build/common.gypi'],
+  'targets': [
+    {
+      'target_name': 'webrtc_common',
+      'type': 'static_library',
+      'sources': [
+        'config.h',
+        'config.cc',
+      ],
+    },
+  ],
+}