Add prefix arg support prelude-update-packages

With a prefix arg it will update all installed packages.
Merge branch 'master' of github.com:bbatsov/prelude
Fix epl-upgrade invocation
[Fix #433] Disable problematic binding M-[
Simplify sexp wrapping code
Add wrapping commands to ielm-map
Improve tab's behavior

It now does both indentation and completion (when supported)
Pull in upstream changes