Enhancement to auto complete current path

Enhancement to auto complete current path, https://github.com/FredrikNoren/ungit/issues/37

Uses custom jquery-ui and get rest API to get all directories in current path and allow users to select on the go.


![screen shot 2013-09-05 at 18 10 51](https://f.cloud.github.com/assets/5281068/1103989/25115f2e-18d5-11e3-9a2f-3ac6a1464f4d.png)