EV follow-up

[shorowit]

Keeping track of any issues/questions after the EV PRs merged:

• Fix runtime speed regression for stochastic schedule generation Fix stochastic schedule generation runtime #1933
• Address a few TODOs for documenting methods in schedules.rb
• Why did hot water-related stochastic schedules change? Is it because Activities found even when the occupancy is zero (stochastic schedule generator) #1023 was addressed. Need to update changelog.
• Changing the EV charger location had no effect (see here), should it?
• Can we generate stochastic schedules for EV charging when using the PlugLoad approach?
• Can we use a smooth default schedule for EV charging when using the PlugLoad approach?
• Missing "and EV driving" here and here; also add the new output to the changelog?

[shorowit]

Just discovered that the update_hpxmls task takes more than 2x longer than it did before to regenerate our sample files. Seems to be caused by the EV schedules PR. Considering we only have a few dozen sample HPXMLs w/ stochastic schedules, the hit on performance must be huge to make the entire task more than double.

I'll take a look to see if I can figure out what happened, but the entire stochastic schedule generation code was refactored so hopefully it doesn't require major surgery...