Netlist updates and bugfixes
- improved convergence code (max(epsilon) instead of sum(epsilon))
- identified needless updates
- changed NE555 discharge current to a value in the order of the datasheet
- improved dynamic time-stepping. 

Dynamic time-stepping is not used by any current implementation right now since any fast discharge will be resolved to mV levels imposing nano-second timesteps. Great and exact but deadly for performance.