Two TemperatureSensor bugs fixed
More TemperatureSensor typos fixed
Stop advancing sequence after it is cancelled
Control updates

Added control.Bind for auto-updating one variable based on an
expression.
Updated control.StateMonitor to add option for running a sequence when
the condition becomes OK again.
Add processing function parameter.
Generate get_centroids function
Removed line from tracker.
Fixed manips to use interp rather than get
Fixed typos in control.Bind
Stop comparing strings with "is"
Accept lists in place of sequences.
Consolidate child step logic

Adding event listeners.
Checking that child steps are all instances of BaseStep.
Allowing all iterables in place of sequences.
Improvements to sequence controls

Added docstrings.
Added max/min to Bind.
Bind only calls set if necessary.
Remove default max/min from PID.
Listen to events on StateMonitor trigger_step / reset_step.
(Renamed step to trigger_step).
Added StateMonitor.cancel_on_trigger option.
Added test examples for Bind and StateMonitor.
Merge branch 'develop'