Geometry Notation Standard

[arunxdas]

in-code notation for geometry (Rotations, Transformations, vectors, etc) should be standardized. Initial discussion based on http://paulfurgale.info/news/2014/6/9/representing-robot-pose-the-good-the-bad-and-the-ugly

We will begin by brainstorming ideas within the "geometry notations standards" page within the ditto docs. Once finalized, the standards, along with frame definitions, will be published there.

[arunxdas]

Markdown page with discussion can be found here: https://github.com/wavelab/libwave/blob/issue_33_geometry_notation/docs/ref/geometry/geometry_notation.md

[leokoppel]

Assigned to myself to add to Doxygen