Create an Employer (ie. company/business) in VETtrak with the specified name. 

First checks to see if an employer with the specified name already exists, as VETtrak cannot have more than one employer with the same name. If it does, the existing employer is returned. If no matching employer exists, a new employer record is created with the specified name, and the new employer returned. The Empl_Identifier field in the TEmpl will contain the new employer's identifier. 

AddEmployer can be used to ensure an employer exists in VETtrak, before proceeding with other functions. 

The returned Employer is represented by a TEmpl. 

A token is passed for authentication. If the authentication fails, or other errors occur, no client is returned. The result of the authentication is represented by a TAuthenticate object. 

This function has security level "Protected", and can only be accessed by users that have explicitly been granted permission to the API.

[WebMethod(Description = "Creates a new employer with the specified name")]
public TAuthEmpl AddEmployer(string token, string employerName);