setting error handlers in wrong spot?

[jaydiablo]

I noticed that you're setting the error/exception handlers in the sendException method of the bugsnag service, however, I believe this is only ever encountered when a dispatch.error is handled (or a user calls the method directly).

https://github.com/nickurt/zf-bugsnag/blob/master/src/ZfBugsnag/Service/BugsnagService.php#L46

The PHP error/exception handlers should probably be configured in the constructor of the service so that they can catch errors/exceptions thrown outside of the dispatch cycle.

I'm currently testing implementing this plugin in a ZF2 app, I'll try to submit a PR after I'm done with some testing.