computeWwaypoint now return a vector of waypoint_t instead of waypoint6_t

include/bezier-com-traj/waypoints/waypoints_c0_dc0_c1.hh

include/bezier-com-traj/waypoints/waypoints_c0_dc0_dc1.hh

include/bezier-com-traj/waypoints/waypoints_c0_dc0_dc1_c1.hh

...ude/bezier-com-traj/waypoints/waypoints_c0_dc0_ddc0_c1.hh

...bezier-com-traj/waypoints/waypoints_c0_dc0_ddc0_dc1_c1.hh

...r-com-traj/waypoints/waypoints_c0_dc0_ddc0_ddc1_dc1_c1.hh

...traj/waypoints/waypoints_c0_dc0_ddc0_j0_j1_ddc1_dc1_c1.hh

...j/waypoints/waypoints_c0_dc0_ddc0_j0_x3_j1_ddc1_dc1_c1.hh

...j/waypoints/waypoints_c0_dc0_ddc0_j0_x5_j1_ddc1_dc1_c1.hh

include/bezier-com-traj/waypoints/waypoints_definition.hh

src/computeCOMTraj.cpp

src/waypoints_definition.cpp