SimpleSAMLphp attribute to be used as unique identifier for the user

For now SimpleSAMLphp attribute to be used as unique identifier for the user and if you want to use the attribute is multivalued , it won't work. for that i applied a patch ( Now it will allow multiple values) , If the attribute is multivalued, the Both values will be used and Field can be pipe separated, which allows for fallback attributes to use.

Example :

eduPersonPrincipalName or eduPersonTargetedID or mail ( for example consider these three are the attributes you want to use and you can use like this by separated by pipe http://schemas.xmlsoap.org/ws/2005/05/identity/claims/emailaddress|http://schemas.xmlsoap.org/ws/2005/05/identity/claims/eduPersonPrincipal...|http://schemas.xmlsoap.org/ws/2005/05/identity/claims/eduPersonTargetedID )