AES: Fixed wrongfully hardcoded $return_format/$input_format (non-security)

Added conflict resolution for wikitext heading names

Some enhancements to the error handler. It replaces out ENANO_ROOT for security, and if the warning is from dbal.php and ENANO_DEBUG is set, prints out a much more verbose message.

Changed var_export() calls to use "true" as second parameter. Not sure which PHP version it was added in, but I could have sworn it wasn't there last time I checked.