Feature request: include clockwork plumbing in error reporting

[brentsnook]

We recently had problems with our event definitions where an :if proc had the incorrect arity. We only discovered this by eventually finding the clockwork error in the logs. We'd like to be able to configure an error_handler and have it also pick up any errors with event definition.

At the moment only the contents of the event is handled by the error handler:

clockwork/lib/clockwork/event.rb

Line 58 in cc1b7c9

@block.call(@job, @last)

It would be great if any tests and anything else related to clockwork plumbing were covered by the error handling - moving it out to the manager might be better:

clockwork/lib/clockwork/manager.rb

Line 167 in cc1b7c9

log_error(e)