Implemented upload to webstore (fixed #153)

review: @devoncarew

![screen shot 2014-02-21 at 4 37 00 pm](https://f.cloud.github.com/assets/332168/2236297/e2c88392-9b59-11e3-9ad2-41b000a9db8d.png)
![screen shot 2014-02-21 at 4 37 06 pm](https://f.cloud.github.com/assets/332168/2236298/e6ac51aa-9b59-11e3-8421-4bcdbfd4201d.png)
![screen shot 2014-02-21 at 4 37 35 pm](https://f.cloud.github.com/assets/332168/2236299/eac6da94-9b59-11e3-93ed-eb2ba5b52dce.png)
![screen shot 2014-02-21 at 4 38 25 pm](https://f.cloud.github.com/assets/332168/2236300/ef0d0c36-9b59-11e3-906c-811305df835a.png)