Adding part of client.pp code into new class
backupninja::client::defaults in an attempt to avoid duplicate
definitions inside backupninja::client::key.

Conflicts:
	manifests/dup.pp

Conflicts:
	manifests/dup.pp

add a $destdir variable requirement

already (it is unecessary to set them when they are already set to the
defaults): testconnect, sign, keep, bandwidthlimit

I also unset because they were not set to the defaults: $tmpdir =
"/var/tmp/duplicity", $nicelevel = 19. The defaults for these are:
$tmpdir = "/tmp", and $nicelevel = 0. The example configuration files
included in backupninja are confusing about these, so I've just
clarified those in the upstream source.

Then there were a couple options that were set to values that I think
should not be set: $password = "a_very_complicated_passphrase" -- I
dont think this should be set by default at all, because people will
accidentally use this passphrase by default (yuck). People should be
forced to set this. I also reset the $destdir = "/backups" setting to
be false. This value must be set, but I dont think it should be set by
default.

Checking whether an exported resource is already defined
at backupninja::server::sandbox, otherwise puppet will try
to redefined them each time a backup resource type is invoked
with the same arguments (such as $directory), raising an error.

merge this commit, because it also includes the package installation
bits that we are doing a different way

* update the README to be more clear about how this works, provide
more examples and included details about the addition of the
backupninja::client::duplicity class

Checking whether an exported resource is already defined
at backupninja::server::sandbox, otherwise puppet will try
to redefined them each time a backup resource type is invoked
with the same arguments (such as $directory), raising an error.

fix rdiff-backup class name, "You can use Aa-Zz, 0-9 and underscores in variables, resources and class names." which means no dashes in class names either

remove redundant case statements which tested to see if the package ensure version variables were set
changed the $rdiff-backup_ensure_version variable to $rdiff_backup_ensure_version as dashes are not allowed in variable names

create subclasses for maildir and rdiff-backup. If you are using these features of backupninja, you'll want to switch to doing "include backupninja::client::maildir" for the machines that need it and this will pull in backupninja::client, so you don't need to include that anymore if you were explicitly doing so for those machines (although it shouldn't hurt). Right now what using these new subclasses will get you is dependencies on needed packages, but in the future there might be more.