The View3d.project method no longer allocates Point2d objects.

The allocation is now upon the caller, who can choose a more efficient
way of managing the points. In the case of XS3D nothing is actually
gained from this, but this technique is used by StarCat (unreleased at
this time) to eliminate all memory allocations which should improve
performance noticeably.
Corrected view angle documentation and defaults.

Turned out that I stood on my head when I updated the documentation
about the orientation and angles. The view angle x-component is the
direction in which we're looking, and 0° for the y-component means
we're looking along the flat of the equator (it's not 180°). Duh.