humanoid_planner_2d: Getter for path costs from SBPL

Conflicts:

	humanoid_planner_2d/include/humanoid_planner_2d/SBPLPlanner2D.h
humanoid_planner_2d: adding option to find SBPL overlay, reducing output
humanoid_planner_2d: check if goal / start reachable before planning
gridmap_2d: adding external access to individual cells, allow recomputation of distance map
gridmap_2d: Adding conversion back to OccupancyGrid msg

Conflicts:

	gridmap_2d/include/gridmap_2d/GridMap2D.h