Thanks for your help!
Pull Requests go into the branch master. The gh-pages branch is a presentation of the master branch at the last given release.
Whenever you change code, make sure you run the test suite before sending a pull request. Please add tests for any features you add to the code base. We're using QUnit for testing.
We're looking forward to splitting URI.js in several files, each dealing with a specific domain, to make the 1800 lines of code more bearable to work with. This will lead to using Grunt to build a distributable version (and the removal of build.html). We're not sure when we'll get to this. If you want to pitch in, just holler!