Node

A representation for a node on the server's tree. A Node is either a Synth or a Group.

'''Note''' that if the node is a group, all messages send to the node which are not specific to a Synth or Group, i.e. all messages found in this class, will affect all child nodes of the group. For example, if release() is called on a Group, the underlying setMsg is propagated to all Synths in the tree whose root is this group.