This commit introduces two new functions in 'url_encoding.py' which
centralize two common patterns for constructing redirect URLs. It
also migrates the files using those patterns to use the new
functions.
When you send a message to a bot that wants
to talk via an outgoing webhook, and there's
an error (e.g. server is down), we send a
message to the bot's owner that links to the
message that triggered the error.
The code to produce those links was out of
date.
Now we move the important code to the
`url_encoding.py` library and fix the PM
links to use the more modern style (user_ids
instead of emails). We also replace "subject"
with "topic" in the stream urls.
Extracting this helper library will help us avoid an import loop
between notifications.py and message.py (with bugdown in between).
But in addition to that, it's a more natural model, since some of the
uses for these functions weren't part of the notifications code
anyway.
Graham Bleaney
Steve Howell
Tim Abbott