AS7-4694 JBAS014478: Could not find timeout method

* trap failure to recreate timer from persisted state and log a warning message instead

Note that I had made a start on cleaning a lot of this up, but Stuart Douglas informed me that a big refactor in this area was already under way. The work that I did can be inspected at https://github.com/sfcoy/jboss-as/compare/AS7-4694 if anyone is interested.