Do not interfere with errors that were suppressed by the @ operator.

[netpalantir]

While working on a legacy project, I noticed that execution threw a different set of error when Ignition was enabled. I noticed that the project makes use of the "@" operator, which suppresses some errors. Ignition is not taking this into consideration, and it will throw new exceptions even for suppressed errors.

This is because when you register an error handler, it will fire regardless of error suppressions, and one should check for a magic error_reporting value to detect that it was indeed suppressed. If the error is not being suppressed, then this value will be -1, as we set it originally.

My code checks for that special value, and if it finds it it return immediately, so Ignition does not fire.

[guiiamorim]

I would like to see this merged, just fixed an error on a legacy app that I installed ignition on. Had to extend the Ignition class into a custom class and override some of the methods to make it work with @include and @filemtime.

[AlexVanderbist]

Awesome, thanks for the great PR with tests!