Makes pull into a mob verb

And so dies the last of the atom verbs. Anything for a less laggy right click menu. Same deal as with examine and point. The verbs -= /atom/movable/verb/pull I removed weren't actually needed because start_pulling already checks for anchored, so you still can't drag MULEs, chairs and mechas (yes I tested it).
Seeing how observers will be able to point, won't creating the pointer-arrow here make it possible for them to spam pointer arrows visible to the living?
Would be neat if the decal could be made visible only to those that can see the pointee, but if not it should probably be moved up to /moving/living/pointed()