Merge lp:~jjacobs/methanal/better-submission-failures into lp:methanal

The new way submission failures are displayed is quite a bit more intrusive than previously, although I see this as a good thing. The ability to toggle the visibility of the Javascript traceback could make certain things easier to debug.

I'd appreciate comments on the design, usability and whatever else.

I don't really have too much to say about this; it seems like a step in the right direction. As a general point of application design, form submission shouldn't fail, but in the case where something goes wrong, the user shouldn't be lead to think that the operation they were attempting to perform succeeded when it didn't.

> I don't really have too much to say about this; it seems like a step in the
> right direction. As a general point of application design, form submission
> shouldn't fail, but in the case where something goes wrong, the user shouldn't
> be lead to think that the operation they were attempting to perform succeeded
> when it didn't.

One of the scenarios where this comes up is where an error design to occur does. For example, submitting a form that results in some external API call that fails for some reason (authentication failed, invalid/missing data, etc.)

Perhaps this case shouldn't be a submission failure, but for now it is. I'd be interested to hear any further ideas on this topic.