ModuleConfig `parse()` method does not require file (task #3495)
ModuleConfig `parse()` method does not require file (task #3495)

From now on, the `parse()` method of the ModuleConfig does not
require the configuration file to be present, as parsers can
return defaults.

If anything but an empty configuration is returned, it is still
validating with JSON Schema.

QoboLtd/cakephp-utils,QoboLtd/cakephp-utils,QoboLtd/cakephp-utils