Fix for `debug` command (invocation of Safari Web Inspector for debuggin...

...g the app running in iOS Simulator):

* Fix: invocation now also works if the *iPad* is being simulated (not just the iPhone)
* Fix: functionality should now also work when Safari runs in localized (in a different UI language)
* Fix: bug in exit-code recording in class Sbawned
* Improvement: proper error handling and reporting
* Improvement: prompt doesn't redisplay until after the spawned tasks exit.
* Improvement: AppleScripts now try to turn on access for assistive devices on demand - on 10.9, unfortunately, this requires the user to perform multiple steps and then rerun the command; on 10.8, providing an admin password is enough.
* Improvement: AppleScripts now time out with a - hopefully - helpful message, if the relevant menu items in Safari cannot be found.
* Improvement: AppleScripts now only *activate* (as opposed to launch in the background) Safari when it's truly necessary.
* Improvement: AppleScripts now report errors.