/*
* Set user authentication for a MusicBrainz::Client object.
*
* This method is optional. It only needs to be called if you want to
* submit data to the server and give the user credit for the
* submission. If you want to submit data anonymously, don't call this
* method. Returns true if the authentication was successful.
*
* Aliases:
* MusicBrainz::Client#authenticate
*
* Examples:
* # connect as user "MrMusic", password "s3kr3tp455w0rd"
* mb.auth 'MrMusic', 's3kr3tp455w0rd'
*
* # connect as user "MBrox", password "hithere!"
* mb.authenticate 'MBrox', 'hithere!'
*
*/
static VALUE mb_client_auth(VALUE self, VALUE user, VALUE pass) {