upgrade Vagrant 1.1+; use standalone omnibus cookbook

We now use an `omnibus` cookbook that lives in the opscode-cookbooks
organization (and is released to the community site). Vagrant support
has also been removed from the bundle and upgraded to use Vagrant 1.1+
which is now installed system-wide.
Update example omnibus config files for new config format

The Omnibus config file is now `mixlib-config` based.
Projects are now built using the `omnibus` CLI
`Omnibus.root` is now `Omnibus.project_root`
`omnibus` cookbook is now pulled in using Berkshelf

The `omnibus` cookbook has been refactored and lives as a properly
released cookbook (along with it's dependencies) on the community site.
update dna.json files for new attribute naming

https://github.com/opscode-cookbooks/omnibus/blob/master/attributes/default.rb
gitignore some additional build-time tmp assets
trailing whitespace and typos