Add 'remote_services' plugin

Returns a hash of services that are listening for
connections.
Merge pull request #7 from ziadsawalha/remote-services

Add 'remote_services' plugin
Merge pull request #6 from ryandub/master

Add plugin to report ohai-solo version
Merge branch 'master' of github.com:rackerlabs/ohai-plugins
Add Vagrantfile for easy plugin testing