Quick command use and saved last commands

[jchannon]

Attempt at #9.

Beautify also ran against source.

[Acconut]

The Panel shouldn't be closed by exit. It depends whether the user closes the panel or terminates the process, see https://github.com/Acconut/brackets-nodejs/blob/master/main.js#L248-L254.

[Acconut]

This is quite a lot, I'll have a look.
But I'm not sure yet whether I like the exec-panel's removal.

[jchannon]

To summarize, I've removed the exec modal and put a textbox on the terminal
panel.

The terminal can be opened via Alt+T

The last commands are stored in an array up to a max of 10 items

The up and down keys when the textbox has focus will go through the last
commands array and populate it with the command. You can then hit enter or
click the arrow button to execute it.

[Acconut]

Another option would be to use the new datalists (http://davidwalsh.name/datalist). It's a bit fancier because you can see the last commands and not only navigate through them. What do you think?

[jchannon]

I guess its an option. I did the keyup/down thing to keep it similar to how
it works in a Terminal :)

[Acconut]

datalists work with keys up and down, too.
I'll try it out and then we can compare :D