Minor refactoryings
Telling the backend when a new source is created - backend sends object back including its new ID
Extended insertSource to create a stream that streams back the stored objects
Added bodyParser to parse incoming JSON
Added POST on /admin/sources to create new sources objects - newly created object including ID is returned
Added streamify helper that creates a stream from a function with nodeback and also keeps the this/self pointer
Added busy flag that disables all editing while waiting for a reply from the server
Added delete and save functionality - delete not complete yet
Added Restangular config that makes it use _id as id field
Added backend calls to get single source, update source and delete source