Can return a string of the form "5:35:09pm", as opposed to "17:35:09"
If "useTwentyFourHourTime" is "true", returns time in the form "17:35:09"
If "showAMPMIndicator" is "true" it will include the "am" or "pm" text,
otherwise it won't.
Identical to the "elapsedTime(String logMessage, String aFilter)" method, except it
will only show the message if the filter "TIMING" exists in Debug's filter list.
Returns true only if this instance can change after it is created.
The default implementation returns false because instances of this
class can't change; subclasses that introduce mutability should
override this method to return true.
Identical to the "startTiming(String logMessage, String aFilter)" method, except it
will only show the message if the filter "TIMING" exists in Debug's filter list.