Email notification improvements

We have delivered some big improvements to the email notification system in last few days:

  • now delivers neater looking emails (no longer plain text, but HTML based rich text).
  • More types of notifications are sent: for example when someone accepts an invitation, the other owners of the project are notified beside the newly joined collaborator.
  • Robustness: a number of bugfixes related to email sending (copy text, links in individual messages, delivery problems) have been resolved.