Enhancement: Add Fold All Option

[kyle-charlton]

It would be great to see an option to fold all, it would make editing/navigating CSS files a little easier.
It would be nice if there was a keyboard shortcut to trigger fold all/unfold all.

I tried to look it up to see if ACE was capable of it and I found a thread on Stack Overflow where someone was looking into the same thing.

https://stackoverflow.com/questions/12823456/programmatically-fold-code-in-ace-editor