apt::force: Added 2 parameters for automatic configuration file handling...

...; fixes #modules-1306

when updating or installing newer packages with apt::force and you have changed previous
configuration files aptitude or apt-get will prompt what to do. You can suppress that
by pre-define the action with cfg_files parameter (new, old or unchanged and its backward
compatible if not defined). With a second optional parameter cfg_missing you can force
your provider to install missing configuration files as well.

Signed-off-by: Martin Seener <martin@seener.de>
I never said it was wrong, I said I had a severe dislike for selectors and I'm not the only one that shares that view. Stating that selectors are a 'best practice' is debatable, as `case` statements can be used just as well.

From that same language guide:
```
Control Expressions

The control expression of a case statement may be any fragment of Puppet code that resolves to a normal value. This includes:

Variables
Expressions
Functions that return values
```

We try to avoid selectors in most new contributions because of their readability issue, regardless of perceived best practices. We also don't do 'big bang' things like rewrite all all selectors to something else, we do that gradually.

Since this is new code, I'd like it done properly, not merge it in and need to after it to fix it.