Opt move cookie init to backend and add optional ignore connection error

[elwinarens]

Work In Progress (WIP). Would like to add unit tests, but have confirmed this is working locally.

The current setup does a few things different:

• Fetching of the cookie config is moved to the part where the user authenticates with the backend, iff the config is None.
• A connection error exception can be optionally ignored by setting CROWD_RAISE_CONNECTION_ERROR to False. By default an exception is thrown, adhering to the request by you to not have a change in behaviour by default. The result will be that the user can no longer authenticate and will be logged out once the cookie/token is expired.

Happy to hear your thoughts

[bellarc]

@elwinarens has the owner of this repo acknowledged this change? I wonder if @pmuller is still maintaining this project at this point.