Add new test data

All test data for friendly blockers for king, knight, and pawn moves.
Pawn two-forward moves behave a bit like sliding moves so they are
defined separately from the rest.

Sliding moves take more precision as destination squares on the
opposite side of the blocker cannot be included.

In this commit testing of the attack boards was removed. The
algorithm that had been used to accumulate the value to compare
against the properties in Board was too simplistic to work with
multiple pieces on a board. A more complete solution is needed.