Make the creation of default [bw]tmp-rulesets configurable

[mcgege]

As I'm configuring the rules for btmp and wtmp on my own, the default rulesets conflict with my rules.
With this change you can disable the generation of the default rules like this:

class { '::logrotate':
  defaultrule_bwtmp => false,
}

[juniorsysadmin]

@mcgege This PR needs a rebase. Are you still interested in merging this?

[mcgege]

@juniorsysadmin Sure I am ... will do this the next days

[mcgege]

@juniorsysadmin I have now rewritten the patch and expanded the switch to disable all base rules (although the base rules still contain only rules for btmp and wtmp - but this might change in the future). Therefore the parameter name also changed:

class { '::logrotate':
  create_base_rules => false,
}

[juniorsysadmin]

@mcgege Thanks for this. Are you able to add some appropriate puppet-rspec tests as well?

[mcgege]

@juniorsysadmin I hope that's what you expected - my first try in rspec :-)
There should also be a section in the readme to document these global settings ...