Option to reset states to initial state

[jmaguire1]

Simulator.reset_time updates the time and schedule, but there isn't an option to reset the state of the dwelling (e.g. temperatures, battery SOC, etc.) to their original values. We should add an option to do that. Initial states should include:

• Envelope states
• Equipment states (water heater temperatures, battery SOC)
• Equipment mode, cycle counts, and other state variables
• Envelope zone temperatures and boundary surface temperatures (and t_prev)
• Envelope humidity

Also make a function that saves the initial_state variables and have that save after the initialization. Then a user can reset it to a different time if they want later.

Note that a deepcopy will produce identical results. The goal should be to produce identical results before and after reset_time is called.