This block adds the following features to Buildings.Controls.OBC.CDL.Reals.PIDWithReset.
y_neutral and the tracking error is zeroed out to prevent windup.
Typically this neutral value should correspond to a condition that
applies the minimum control effect, i.e., valves/dampers closed, 
VFDs at minimum speed, etc.
enabled
the controller behaves exactly as
Buildings.Controls.OBC.CDL.Reals.PIDWithReset.
Furthermore, the controller output is reset to y_reset at enable
time.
heating
the controller behaves as
Buildings.Controls.OBC.CDL.Reals.PIDWithReset
except that the sign of the measured and set point variables is reversed
so that the controller may for instance provide a heating function if 
it was originally configured for a cooling function.
Furthermore, the controller output is reset to y_reset at 
the time the operating mode changes.