Add ability to install vagrant plugin from a local or remote source

[logicminds]

I have some custom gems that are not in ruby gems.org and I would like the ability to use the vagrant_plugin resource to install the plugin from a local http server or from local disk.

vagrant_plugin{'some-hipster-plugin':
  ensure => present,
  user     => 'some user',
  source => '/tmp/hipster_feature.gem'
}

vagrant_plugin{'some-remote-hipster-plugin':
  ensure => present,
  user     => 'some user',
  source => 'http://the-interweb.com/hipster-remote-feature.gem'
}

I would expect the code to download the remote gem and then install the gem since vagrant cannot install from remote sources.