Added pretty formatting via a popup menu.. 

However the editor needs to be the active editor for the formatting to
work. I still need to work on this, so keeping this in a branch for now.
Used gherkin formatter to do pretty formatting.
Got pretty formatting working in plugin using Gherkin formatter..

However still needs some cleanup, and there are funnies still with the
popup menu action. Currently the editor needs to be active for it to
work. When I get that tidied up I will merge to Master.
Got pretty formatting working correctly fixes #10

Switched to viewwerConfiguration effectively moving the context menu to
the editors context menu rather than the file systems context menu.
Autoformatting now works.. could still use a short cut, will create a
new issue for that.