Add support for deleting keys with delete button

[helgrima]

Although Edit menu suggest that delete key functionality could be accomplished by using delete key it is accomplished by backspace key. This is only minor inconveniece, but https://github.com/rocket/rocket uses delete key.

[emoon]

So would just adding that delete perform the same action as backspace be ok?

[helgrima]

Yeah. I think that would be great!

[emoon]

Alright! I get it sorted :)