SO(2)/SE(2) Support Added

Added support for SO(2) and SE(2) Lie groups. Small bug fixes and streamlining of branches also added.

v2.1.0

Merge pull request #44 from utiasASRL/C++11

Redo Kai's change on using default copy/move constructor/operator for SO3/SE3 classes

v2.0.0

What's Changed

• Upgrade lgmath to use Eigen3.3+ and c++17 by @cheneyuwu in #42

Full Changelog: v1.0.0...v2.0.0

Release for C++11 and Eigen3.2.5

The main branch is moving forward to use C++17 and Eigen>=3.3.7, so creating this snapshot for code not compatible with the new versions.