Adding unscented Kalman filter.

Still need to update UKF tests
Merging changes from origin
Fixing issue with uninitialzied sigma points
Merge remote-tracking branch 'upstream/indigo-devel' into indigo-devel
Fixed UKF localization node and updated tests. Also fix CMake install targets
Fixing UKF name in doxygen docs
Merge pull request #109 from ayrton04/indigo-devel

Merging UKF addition