Exceptions: Copy from memory to store X on startup

[NickCraver]

One common error pattern we've seen is that exceptions logged to the default store (e.g. due to a startup ordering issue), should be logged to the destination store in every case we can think of.

When an error happens and gets added to the memory store, then we configure say a SQL store later...let's move the exceptions on a store swap if possible. /cc @deanward81

[NickCraver]

This is solved by aaa3642