Math nodes revisited!

Written for Nodekit by Richard Radlherr on 2008-06-12

Existing Math nodes are substituted by more flexible nodes so that the number of nodes in Math is very reduced.
All new Nodes can now be triggered in the following ways:
- Always: means that changing Operands will cause an
  immediate update of the result of that node.
- OnCreate: The result of the node updates on a "Create" command.
- Global: The result of the node updates when a sync signal arrives.
Currently all older nodes in Math space are also available but they will be removed after refactoring our patches using theese nodes.