contrib: add dokku client shell script

This is adapted from the one I use in my shell profile scripts. This
kinda-sorta-maybe acts like the `heroku` or `deis` commands and does
some clever reorganization of data before sending it to the server.

To use the app name generator, install the `elfs` rock from Moonrocks.
Reorganized list of available datastore plugins
Change tables to be left aligned
Better formatting of plugin tables
Ensure tables have proper width
Merge pull request #771 from progrium/doc-changes

Doc changes
Import ssl certificates

Also ensures output is stored in proper tls directory

Closes #518
Merge pull request #772 from progrium/518-import-ssl

Import ssl certificates
Disable nginx vhosts via `dokku config:set myapp NO_VHOST=1`. Closes #485
Merge pull request #773 from progrium/485-native-no-vhost

Disable nginx vhosts via `dokku config:set myapp NO_VHOST=1`. Closes #485
Remove reference to no-vhost plugin that is now in core
Add the ability to customize an app's hostname using the nginx-hostname pluginhook

Closes #254
Merge pull request #774 from progrium/254-nginx-hostname-hook

Add the ability to customize an app's hostname using nginx-hostname pluginhook
Add PLUGIN:help command to each plugin
Merge pull request #775 from progrium/plugin-help

Add PLUGIN:help command to each plugin
Release 0.3.2
Update man page for new commands
Merge pull request #776 from joliv/master

Update man page for new commands
Added environment variable for base container

In order to be able to use a different base image i have added another
environment variable where everybody can switch the used base container
for the applications directly through the environment variable
DOKKU_IMAGE or with the help of the dokkurc configuration.
Added openSUSE support

I have done the first steps to get dokku running for other distros like
openSUSE. I have simply replaced the important places within the core
plugins with a check for DOKKU_DISTRO that gets exported by dokku
itself. It just replaces the apt-get and service start/restart/reload
functionality with the openSUSE counterparts.