Audit and update documentation

[rtheunissen]

The map method was added to Set in v1.2.7, but the documentation on php.net does not include that. It would be valuable to do a complete audit of the current documentation to see what else might be out of date and patch them all.

[Girgias]

As I was just looking at the DS docs (vaguely via a QA script) the easiest bit to know if the doc is up to date would be to have a stub file that then can generate the PHP docs by using something like:

php ../php-src/build/gen_stub.php --replace-classsynopses --replace-methodsynopses ds.stub.php ../docs-php/en/

Or

php ../php-src/build/gen_stub.php --generate-classsynopses --generate-methodsynopses ds.stub.php ../docs-php/en/