Fix simulation release: end of March
This release incorporates a completely new simulator (1500 lines F#) which cannot have the "propagation" bugs affecting the old simulator and is also typically about 10X faster. Simulation should now be completely deterministic.
- The simulator is still not fully tested but appears to work for the (large) examples where the old simulator failed.
- The simulator is not yet optimised: additional speedup is possible but for ~ 500 components it is probably not needed.
- Added benefit is that wave simulations are now much faster than before
- Other problems with Issie remain unchanged