Restructure `clicraft maint`

Change the functionality of this script to do several things. In
addition to generating a regex database from the english minecraft
language file, it can also generate an example cmd.sh action script
that wraps `clicraft cmd` and makes it easier to pass commands to
the server.
Add example `clicraft cmd` script

Add an example script that wraps `clicraft cmd`. It's probably best
to explain how this is used by example. If enabled through e.g.
`clicraft enable cmd whitelist`, then `clicraft whitelist ...` is
equivalent to `clicraft cmd -v whitelist ...`.