Update for 0.2.0
Update description
Determine PE version using fewer regexes
Add function to output PE package name
Explicitly fail when run on windows

The staging module doesn't yet support windows in a meaningful capacity,
so abort early instead of breaking everything.
Use more sensible download options
Split up the staging and actual execution classes
Add explicit fail and force_upgrade for masters

Per (pe_upgrade-#7) it is possible for a master to forcibly downgrade
itself if the master is upgraded but has old data referring to an old
version. The patch supplied would disable upgrading a master but had the
unfortunate side effect of silently refusing to upgrade. This adds an
explicit failure to prevent masters from being modified by accident.
Clean up and centralize validation code.

This fixes (pe_upgrade-#9).
include staging for staging_root
Validate default facts as well as manual facts
Construct full download_url in pe_upgrade::staging
Properly scope inclusion of top level 'staging'
reuse staging_root variable
Expand pkg name resolution for ubuntu/debian
Remove unused .gitignore
Split up downgrade and master checks
Add documentation for mode, server, certname vars
Add verbose mode to pe_upgrade
Explicitly pass variables as parameters