Test resume functionality

[brinchj]

Currently not all threads propagate errors when handling incoming requests. Changing this should make the code easier to follow by removing premature panics and allow us to test the resume functionality.

The idea is to trigger an error, reset the hat system and then resume. At present, just triggering the error causes a panic, which wipes the in memory databases used during tests.

An alternate option: put the test databases in local temporary files and recover the panic. Error propagation seems cleaner, although a true panic would probably be more authentic.