Replace the current vout by a native surface vout
This commit merges the vout module made by Ming Hu in his github project and removes the current vmem/opengl code. This new vout is much faster than the previous: It is able to draw and scale a 720p-h264 video with only few frame drops on a Nexus One. The counterpart is that it uses some non-public and non-documented APIs. Tested on a Nexus One running Android 2.3.4 and a Xoom tablet running Android 3.0 (Honeycomb).