Search api

This pull doesn't contain code which authorizes API calls. Apart from that, it returns search results as expected :)

I was not sure which could be the best authorization mechanism, so I didn't implement it. Also, it is not possible to use Meteor.user() on server side iron router. See yourself: http://stackoverflow.com/questions/20219572/meteor-user-on-iron-router-server-side

PS: I have rebased ESIntegration branch on search_api.