Some very important improvements to your proftpd module

Hello Adam,

I did find your module to manage proftpd. Unfortunately there is some issues that holds me from using it. (Well, I can and did update it locally but this would hold me from updating the module by "puppet module ...".

The changes are:
- Some cleanup -- Just to make git able to track the changes propperly and there was a leftover .swp file.
- Allow configuration of NAT settings
- Allow configuring the template to use for the main configuration