kdtest: Block reconstruction using source patches.

Other tests (via the splat function) do recon with quantized
versions of matching tuples. We take the matched tuples
(via propagated search) and use that to find the original
patches from the source for recontruction.
kdtree: Actually set the 'end' member. Oops.
kdtest: Add a match4.

This is the same algo as the current match() in kdtest,
except that it does reconstruction using patches in the source
image rather than doing the inverse transform.

Almost as good as the propagation algo, but not quite.
cd: Read from changedetection.net dataset.
cd: Hook up processing routines.