Change most of User web service functions to support multiple operation in one call. Adapt SOAP and XMLRPC test client. (REST User test clients wont work anymore till REST server supports array parameter)
* Remove description array => all these information are now into the phpdoc. Remove all call/reference to moodleexternal.php
* Adapt our own REST server to these changes
* Remove Zend REST server as it's going to be deprecated in Zend Framework 1.8
* Remove our own SOAP server as we use the Zend SOAP server
