Support vectors of shape (3) *as well as* those of shape (3,1), but make (3) the default

[translunar]

A bad design decision was made early on, which was to have row vectors and column vectors be represented differently. This needs to be addressed, with all vectors made to have no orientation.

Some functions already do this. One example, good for a beginner, is pqr.uniform_random_axis(); it should return a vector without any orientation.

Traces from https://github.com/autumnsault/pyquat/issues/6