createDiversion
instantiates an object from class of createDiversion
# S3 method for default
createDiversion(name="Unttitled",label,downstream=NA,divertTo,capacity)
a string: the name of diversion to be instantiated
an integer: the code of downstream object
an integer: a unique number, as label
an integer: the code of an object at the diversion outlet
diversion capacity (cms)
a list: an object from class of list instantiated by createDiversion