fixes for 3.0

Hi,

I did some additions to your pe_upgrade module to support PE 3.0 upgrades.

Biggest changes were: 
- Dynamic scoping issues
- upgrade script not provided anymore with PE 3.0, changed to installer (which does upgrades as well)
- a few changes to pass puppet-lint

Kind regards (and thanks for that module!),

Ger Apeldoorn.