Add EigenQuaternion manifold and tests for it. Change-Id: I579a45a2921424a07d03b3b4d9cfcbc0ab529f9b
Ceres Solver is an open source C++ library for modeling and solving large, complicated optimization problems. It is a feature rich, mature and performant library which has been used in production at Google since 2010. Ceres Solver can solve two kinds of problems.
Please see ceres-solver.org for more information.