Initial commit from threejs of branch r51

This commit is directly from the r51 branch/tag of threejs
Revision: ef5f05d71bb33e5811560851547fe4f0bc33e153
Author: Mr.doob <info@mrdoob.com>
Date: 10/1/2012 6:41:40 AM
Message:
Updated README and removed unneeded includes in example.
Use the xml collada element name before using the id if defined
Convert the up axis to Z up during the import
Load the ColladaLoader.js file separately
Fixed the spin-axis for the prop

Something is still wrong here, the prop should be rotating around X, but the correct visual axis is Y