* FIX: Show resend button only if an email was sent
Otherwise, show the "save and send email" button.
* UX: Copy change
* UX: Show feedback when link was copied
The user interface has been reorganized to show email and link invites
in the same screen. Staff has more control over creating and updating
invites. Bulk invite has also been improved with better explanations.
On the server side, many code paths for email and link invites have
been merged to avoid duplicated logic. The API returns better responses
with more appropriate HTTP status codes.
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
Dan Ungureanu
Arpit Jalan
Robin Ward
Sam Saffron
Neil Lalonde
Jakub Arnold