error_reporting -> debuggin topic

[PeeHaa]

Convert and expand the error_reporting topic to a basic debugging topic

[philip]

Something to consider: Has xdebug become a standard in the PHP world? We could refer to it, especially considering it's a PECL extension. Unfortunately it is not documented at php.net though, which limits our ability to promote its use.

And worth noting: setting display_errors at runtime will not work when syntax errors are present.