* If a method has a refpurpose, description, parameters and return
values, it's documented, there's no need for the warning box.
* Add description where there was none. It is usually very similar
to the refpurpose.
* Document ReflectionZendExtension::__construct(), and update
ReflectionExtension::__construct() for consistency.
* In ReflectionFunction::__toString()
* Remove some references to deprecated export() methods.
* Add example for ReflectionParameter::__toString().
We also document the new `$filter` parameter for the `ReflectionClass`
methods `::getConstants()` and `::getReflectionConstants()` and the
respective constants.
Co-authored-by: Christoph M. Becker <cmbecker69@gmx.de>
Closes GH-298.
