fix email abbreviation in apps list
show help output on --help flag. Fixes #150.
add setting for strict-flag-ordering

Allow users to disable interspersed flags and non-flag args. Without
this setting, the following command:

    $ hk run ls -a myapp

runs `ls` on the app named `myapp`. With this setting enabled, it
instead runs `ls -a myapp` on whatever the default app is for the
current directory (based on the local git remotes).