Attempt to authenticate the user, returning a session reference if successful

Return value
	type	description
	session	reference of newly created session
Parameters
name	type	description
uname	string	Username for login.
pwd	string	Password for login.
version	string	Client API version.
Errors
name	arguments	description
SESSION_AUTHENTICATION_FAILED		The credentials given by the user are incorrect, so access has been denied, and you have not been issued a session handle.

• Message has only a synchronous version
• This is a custom message