Show in the user interface message about Case you don't have Access to

[epugh]

Describe the bug
When you bring up a case URL in Quepid that isn't shared with you, you get an empty page.

To Reproduce
Steps to reproduce the behavior:

1. Eric goes to http://app.quepid.com/case/3465/try/3?sort=default
2. He gets an empty case page
3. Look in the console, you see the API sending back a 404
4. See error

Expected behavior
A message that you don't have access to the case. Surface up the message from the API.

Screenshots
If applicable, add screenshots to help explain your problem.

Additional context
The error message ensures you know Quepid is working properly!

[epugh]

so right now the api returns a 404 for either the case not existing or you just don't have permissions.

[epugh]

Drat, accidentally commited the fix in 933ed25.

[epugh]

This is now fixed.