Fix problems with offline action storage.

@bug W-1736109@

@rev amcculloch@
Add dummy error message to actions in incomplete state
Action callbacks registered to all states were assuming state === "SUCCESS" || getError() is an array length >=1
Since INCOMPLETE formerly implied getError() === undefined there were errors.
@rev goliver@
@W-1736109@
Merging origin/amcculloch/master-pending/bugs/W-1736109 into master