title: PouchDB keep polling while offline
body: <p>I am working on a webapp utilizing PouchDB as local database, and CouchDB as central database. One of the reasons i utilize PouchDB is i want to leverage offline support in my app. 
  I've ran into a small issue however. When going offline and going online again, PouchDB doesn't sync anymore. I have to refresh the browsers to get it to start sync again. One solution would be that even though the application is offline PouchDB would keep polling the remote database even though offline, which would lead to that when it's online again the synchro would pick up again. Another solution would be to let the user manually tell the application it's online again and pick up the synchronization from there.</p>
  
  <p>How can i tell PouchDB to start syncing again? If i can do this, i can solve my problem.</p>