W equals one

Hi,

First of all thanks for this extension, loving it :)

So here is a summary (you can walk through commits):

- Added white space checkbox so w=1 can be added/removed
- Fixed icons, changed icons and labels -shorter version-
- Refactored a bit to DRY

![Now it looks like this](http://i.imgur.com/HWKyXAf.png)