Message4570

I'd like to default to jline but I've noticed a few annoying problems 
with it that I'd like to see fixed before we do that:

o disables tab for its completion feature that we don't even use
o doesn't recognize backspace (delete) on my platform (OS X)
o breaks non ascii input

It has a way to disable tab via supplying custom keybindings when you 
initialize it, so we could solve that (it's also supposed to let 
customize bindings in a ~/.jline.keybindings but this is broken)

It actually has code to recognize my delete/backspace key via running 
stty, but this is also broken

I have beginnings of fixes for these issues in the jline code base 
(headius has commit access there), so eventually we'll get this all 
taken care of, but possibly not before 2.5. This shouldn't block the 
release