typedef for time array. objective is to remove numpoints from lower levl methods

include/bezier-com-traj/common_solve_methods.hh

include/bezier-com-traj/common_solve_methods.inl

include/bezier-com-traj/cost/costfunction_definition.hh

include/bezier-com-traj/definitions.hh

include/bezier-com-traj/utils.hh

src/costfunction_definition.cpp

src/solve_transition.cpp

src/utils.cpp