Demo should use relative paths

[vjeux]

http://fooo.fr/~vjeux/nodejs/git.js/demos/repo-viewer/index.html

I tried to test the demo but it doesn't work because it gets files in absolute fashion: GET http://fooo.fr/git.min.js 404 (Not Found) instead of http://fooo.fr/~vjeux/nodejs/git.js/lib/git.min.js

Also, the following suggestion would be kickass http://functionsource.com/post/git-js