Let event's owner can invite non-app user with email address
Merge branches 'dev' and 'invete_nonapp_user' of github.com:xHFT/pencilme-dev into invete_nonapp_user
add invitee from email url and handle this event
Make an email invitee unique
Merge pull request #35 from xHFT/invete_nonapp_user

Invete nonapp user