Cursory look at recent checkins seems to indicate that he wrote all the code.
As the copyright holder of the code he could re-license it the same way even if it was GPL.
As the copyright holder of the code he could re-license it the same way even if it was GPL.
1. There are github commits not by him in the project.
2. There are lots of copyright assertions scattered through the project. The first one I ran into was:
> Copyright (c) 2006-2008 Amit Singh/Google Inc.
but I'm sure there are way more than that.