create a new project wizard

Add a 'New Project...' dialog and top-level button to fix #759. Much of the unrelated changes in the dart and html files are due to fixing some indents that had been using 3 spaces. @dinhviethoa 

![screen shot 2014-01-20 at 10 38 20 am](https://f.cloud.github.com/assets/1269969/1957052/4dda4e48-8202-11e3-84d3-eb25896674c9.png)