v0.3.3

This release adds multiple outputs to the low-level math and function traits. The high-level Shape object has not changed, although internally it now checks that it's wrapping a single-output Function.

• Function and evaluator types now produce multiple outputs
  • MathFunction::new now takes a slice of nodes, instead of a single node
  • All of the intermediate tape formats (SsaTape, etc) are aware of multiple output nodes
  • Evaluation now returns a slice of outputs, one for each root node (ordered based on order in the &[Node] slice passed to MathFunction::new)
• RegisterAllocator no longer binds SSA register 0 to physical register 0 by default. If you don't know what this means, don't worry about it.