creates a new entity of the given entity type
function ECreate input Integer n; input Real HCR "Entity Type HoldCostRate"; input Real VA "Entity Type VACost"; input Real NVA "Entity Type NVACost"; input Real W "Entity Type WaitCost"; input Real T "Entity Type TranCost"; input Real O "Entity Type OtherCost"; input Integer ID "Entity Type ID"; input Real Time "current time"; input Integer attr "reference to the attributes list"; output Integer entity "reference to the new entity"; end ECreate;