support !foo and !! commands

with any shell its handy to re-run previous commands (e.g. to re-run an addon --install command) by referring to the prefix of the command.

e.g.

$ !addon
addon-install --coordinate foo:bar,1.0-SNAPSHOT
$ !!
addon-install --coordinate foo:bar,1.0-SNAPSHOT

Being able to do things like

$ history | grep cheese

would be handy too