Bounce indentation and other improvements

* Add abbrev for 'end' to reindent line

* Add support for bounce indentation on tab similar to js2-mode

* Add support for bouncing between deep indent and continuation indent

* Finer grained control for how hanging braces and parens indent, in
normal indentation and deep indentation

Signed-off-by: Erik Charlebois <erikcharlebois@gmail.com>