changed AgaviRoutingValue setter signatures, assume default values for second argument of createValue() in places where it makes sense, adjusted tests accordingly
some tests for AgaviRoutingValue, changed AgaviRoutingValue::toString() to unconditionally return the encoded value
some tests for AgaviRoutingValue, changed AgaviRoutingValue::toString() to unconditionally return the encoded value, zomg
introduced an interface for routing values, cleaned up docs
some dox