Boilerplate more Point tests

They still need to be implemented.
Create reciprocity tests

This commit expands the tests flexibly. There are certain rules that
should be applicable in all cases concerning topological relationships
between points. For example, the distance between two points should
always be the same, regardless of the direction. The slope between two
points should always be the inverse, depending on the direction.

Lines 25-28 now create a list of all possible unique two-point
combinations, no matter what points we put into the tests, regardless of
the dimensions they occupy. These are then tested in additional
reciprocity tests down the line. This way the tests get more
comprehensive the more points we add, without making it unnecessarily
difficult to expand the tests themselves.

Some of the tests still need to be finished, but I think that this is
quite a bit of progress.
Merge pull request #14 from erget/unit_tests

Unit tests