1. Add a version history
2. Update copyright years across the code base
3. Run format_all.sh
4. Update version strings from 2.1.0 to 2.2.0 in the docs and
elsewhere.
Change-Id: I46d8d479d54bd6002d532785e67342106e73c9ac
Conversions function include Euler Angles to / from Rotation Matrices
and Quaternions. They are generalized for any Euler convention that can
be specified in the arguments. Algorithm is from "Euler angle
conversion", Ken Shoemake, Graphics Gems IV
Change-Id: I7f9ddc0b8d686efca16299d2ba374295744376ce