Rename UnknownRunLock -> UndefinedRunLock
Remove stream-awareness from RunLock
Change semantics of UndefinedRunLock exception

Now convert run numbers to int before doing anything.  However raise
an exception when the run number is less than 6 digit.
Update tests to be in sync with RunLock

1. No need for unsupported stream test because of (8f00a89)
2. Bad run number test still valid since run number < 1E5 (0f7e438)
3. Skip permission problem test
4. Minor attribute renaming for semantic consistency