Reverting code to write fluid and physics properties to Fluid objects
- After exploring using the Network to store all data, it got MESSY.  We're much better off storing values on the fluids.
- I think the idea of create a set of methods on Network that can manipulate the Fluids and Physics objects will remedy all issues we anticipated with this silo'd data storage
Surprizingly few minor changes to make OP algorithm run with new arrangement
- This is of course because the code is almost identical to how is used to be!
Added a lot of 'wrapper methods' to the Network class
- These methods allow code to read and write fluids and physics data by calling a generic method in Network.
- If we want to change how and where data is stored, we only need to change these wrapper methods, and the fluids and physics methods remain unchanged