Add op-notice to "ncp inspect".
Extend tersting for Passable + move NCPCore tests to NCPPlugin.

Tests (partly re-) added and extended, classes moved, some methods
moved.

Some tests will fail if you don't use the next commit as well.
Refine RayTracing.

* Better coverage of block-transitions: One step per axis, dT can be 0.
* Cover one step always, also if no distance is covered.

There might be more false positives, due to newly intoduced bugs, or due
to not all block-transitions being checked (a x + z transition will have
two variations to test extra to the ordinary diagonal path, but only one
is checked).
[BLEEDING] Refine passable-ray-tracing (block-edge treatment).

Previously the max. bounds hitting the block edge would not be
considered as colliding, this can now be controlled with a flag.

If the flag is set, you will collide at offsets of 1.0 for either
coordinate (not if the offset is < 1.0).