Min oa schedule complications

[kbenne]

ControllerOutdoorAir::miniimumOutdoorAirSchedule has not generally had
an effect on turning off ventilation during off hours. This is because
ControllerMechanicalVentilation overpowers the minimum oa schedule and
OpenStudio consistently prefers to write the
ControllerMechanicalVentilation. To rectify this situation, if there is
a ControllerOutdoorAir::minimumOutdoorAirSchedule, then that schedule
will now also be written to the
ControllerMechanicalVentilation::AvailabilitySchedule field when
exporting the idf. This will disable the mechanical ventilation
controller for periods when minimuOutdoorAirSchedule is zero, thereby
removing its interference. Fractional schedule values will still not
have this benefit.

[kbenne]

#1331