Initial Debian and Ubuntu APT support.
Fix Java deployment on Debian and Ubuntu.
Use path to find the service command.
Add missing aptkey suport on Ubuntu.
Disable services only on supported OSs.
Remove the hard-coded Class order.

Apt::Source does not like the hard-coded order of
Class['cloudera::*::repo'], so switch to using before/require on each
class declaration.
Update README.md to indicate Debian and Ubuntu support.
Merge branch 'feature/debian' into develop