added two optimized pathfinds to replace AStar when it's called over short distances

Signed-off-by: Cael_Aislinn <cael_aislinn@yahoo.com.au>
Merge pull request #710 from caelaislinn/astar_hotfix

Adds two optimized pathfinds to replace AStar over short distances
Merge branch 'master' of https://github.com/tgstation/-tg-station