Move msi building logic into omnibus-ruby as a packager.
Clean the build_iteration & handle + in the windows artifact names.
Move the msi version setting into omnibus-ruby.
Pick omnibus-ruby with msi packager support and latest omnibus-software.
Merge pull request #152 from opscode/sersut/msi-packager

Refactor msi building logic into omnibus-ruby as a packager