Add incremental repository search

Hi

I added incremental repository search in option menu.
If you like this, please merge.

![screen shot 2014-07-07 at 10 37 39](https://cloud.githubusercontent.com/assets/819673/3490678/606985da-0577-11e4-97e0-55552d66e496.png)

Thanks,
Yaeda
Please initialize with `var`