Implemented histogram for given image block
Get total for given block
Spacial Pyramid Matching implemented

Poor results suggest there's still a bug in the code.
Moved control on methods up to Test, and performance record to its own file
Fixed Spacial Pyramid Matching. Works like a charm.

The mathematical explanation in the paper was particularly
counterintuitive. The way I append all the histograms values in a single
list for comparison is an optimization over a sum of dot products, which
also simplifies the concept.

MAXRES seems doesn't need to be high, anyway that log2 is the upper bound.
Merge branch 'feature/spm' into develop
Minor fixup and discussion

Got some ideas by playing around with parameters. Seems that spacial
pyramid matching is very reliable on high number of trainings, and does
not need untraining. Also, hik works well on higher numbers.

It is though necessary to make the centroids more... appetible for the
training. I tried with biasing the random initialization, but a better
way seems to be to have the centroid randomly drawn from the image's
distribution.
Merge branch 'release/0.6'
Merge tag '0.6' into develop

Spacial Pyramid Matching as centroid similarity measure.