Upgrade to Meteor 0.7.2 (fixes; merged oplog-with-operators branch).

Meteor release notes:
https://www.meteor.com/blog/2014/03/18/meteor-072-scaling-realtime-mongodb
https://github.com/meteor/meteor/blob/release/0.7.2/History.md

Fixed a coffeescript indentation error which the coffeescript included in
0.7.2 complains about.

Updated the mail-listener2 npm package to latest git HEAD, which fixes
an installation error.