Fixes #660. Move all label namespace handling to models.

[miketaylr]

I want to add some tests to this before we merge.

r? @karlcow

[karlcow]

Ah interesting. I would have thought of putting it on the python side more than the JS side.
but cool! At least it's a working solution. ❤️
Tests are to be added in #272 ?

[miketaylr]

Hitting every nail with my JS 🔨

Tests are to be added in #272 ?

Yeah, we can do that. How long do you think until you can commit the first simple test? @ karlcow@5e2ae26

I can add some more tests specific to the changes in this PR after that.

You mentioned there was a problem with Issue 100, can you explain that again? Maybe I should move the test repo to webcompat...

[karlcow]

Yeah, we can do that. How long do you think until you can commit the first simple test? @ karlcow/webcompat.com@5e2ae26

You mean a Pull request? Because it is committed. :)

You mentioned there was a problem with Issue 100, can you explain that again? Maybe I should move the test repo to webcompat...

Let me reply in #648

[miketaylr]

Yes, a PR.

[karlcow]

Here it is sir. :) #662

[karlcow]

Note for the future. I need to propose something where we handle this on the API side in the python code. More logical and less duplication of code.

[miketaylr]

@karlcow is working on tests, so let's go ahead and pull this in so he's not working against a version of the tree that is going to change.