It avoids unnecessary inclusion and definition

[robot-wrapper] Account for rotor inertias in inertia matrix; by default rotor inertias are assumed to be zero.

Add com-equality-task. Add unit tests for com-equality and se3 tasks. Add functions to compute pseudo-inverses.

Preliminary version of the library (not working yet). In this version I just implemented the constraints, the constant trajectories, the robot wrapper and the task SE3 equality.