Ceres Solver was using an old forked version of FixedArray,
now that we are using absl, we can use the official version
that ships with it.
Change-Id: Ic88d7f6e8a49b928d611f7cbb04172452b322b01
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
Sameer Agarwal