Set of features to safely use PHP-Error on production environment

This is just a merge of all my features from the other pull requests with necessary small fixes to make them work together in concert.

Additionally, you get the printout of output until the failure, and support for CLI scripts.

If you want to have consistent and safe error handling across environments, remove `php_error.force_disabled` on production server, and use `'display_errors' = 0` instead. You can also enable rich error messages during runtime, by using `ini_set('display_errors', 1)`.

This way, your users won't see extensive debug information. But you can log all errors in your framework using callbacks, or send yourself an email if you want. And you can display a pretty user-facing error page in case something happens.