ThresholdAlert Bug Fixes

[rkoshak]

Bug Fixes:

Function	Problem	Fix
stateToValue	The JS function isNaN returns true for empty string causing problems when hysteresis was not set.	Added if clause to handle empty string explicetly.
isAlertingState	The ternary operation in the log statement was not working, showing the wrong value in the logs.	Calculate the return value and save to a variable instead of recalculating it in the log statement.
notAlerting	Testing the wrong timer in record before cancelling initAlertTimer	Fixed if statement
refreshRecord	It's not clear which value is being sent to stateToValue for conversion.	Added log statements before calls to stateToValue indicating what is being converted (state, threshold, hyst).
procEvent	state is already converted to a value before this function is called	Use state instead of converting it again.
procEvent	record[name] should only be initialized once	Don't reinitialize if one of the timers or alerted do not exist. Treat those cases as an error.
procEvent	Code simplicity	Let notAlerting handle the case where we are no longer alerting but there is no endAlert rule to call.
refreshRecord	Missing newline after Init Alert Rule ID in log statement.
Body	Missing case for ItemStateUpdatedEvent	Added case for ItemStateUpdateEvent to handle cases where the default trigger is changed to received update from changed.
Body	It's not always clear when the rule is triggered manually	Change debug log statement to info level when manually triggered.