[request] want getLastMatchDelay(): elapsed time to get last match

[vignesh]

**** feature:
some_match.getTime()

returns a long value in milliseconds representing the elapsed time of the last successful find op (find triggered until visual appeared)

-----------------------------

A method that returns the time that elapsed before the last match succeeded would be very useful for tracking performance.
wait(img,120)
For the above, the match might have happened in say 1 sec or in 30 seconds. A method that would return this value would be pretty useful.