trying some new algorithm for the template match

The numbers the matchTemplate function gave us were not reliable for large needles, so I tried something else and I'm now calculating the MSE of the area and the scene part found matching.

The MSE I map to a comparable percentage number, following
http://en.wikipedia.org/wiki/Peak_signal-to-noise_ratio

One test case is just too far off, so I disabled it after a lot of discussion with Alberto.