Make sure email sending works

[ovidiuch]

• [x] Make sure email sending works, especially when removing accounts -- It doesn't, we need a provider for that, duh!
• [x] Setup a smtp server (maybe gmail), and set the MAIL_URL environment var in start.sh script http://docs.meteor.com/#email
• [x] Change exporting method to user stock mongoexport (https://github.com/skidding/aufond/pull/22#issuecomment-17669406)
  • Easier to import, simpler logic
  • A way to still keep their data for a while in case they need it, but still remove it from the db
  • Create dumps in dump/user/username.timestamp.json
  • This implied extra work, calling a shell method from Meteor, then adding an attachment, going back tot the previous method now that the email actually work (the real problem), and adding profile data as well to make it a bit better