Control SVN users with PHP Subversion API?

Is it possible to create/delete/modify SVN users with the SVN PHP API?

Thank you.

As far as I am aware, you can only do 'svn-manage-users' type commands via the command line. These functions are not available on the PHP API.

The PECL PHP bindings (http://php.net/manual/en/book.svn.php) are, sadly, the only one I have seemed to ever unearth. In theory, the functionality is reasonable (although no user management), but in practice the API is very flaky. Authentication seems to be something of a crap-shoot. It works fairly consistently if you are comfortable with it picking up the authentication from your machine's user, who has already used SVN on the command line.