[WIP] Use trollop option parsing for git reference instead of VERSION file

The VERSION file path as part of the nightly build scripts was not reliable.

Additionally, it feels ugly that the build code used to generate the kickstarts for the appliances needs to have access to the VERSION file from the desired branch/tag/reference.
Is there a way to get required=> true to provide a useful message, I couldn't find it in the rdoc or the interwebs.