Bunch of small fixes

![smallfixes](https://cloud.githubusercontent.com/assets/7573912/5236986/62167c9a-7862-11e4-9605-46a3d4e2417e.png)

-fixed Laser Rifles spawning in place of Laser Canons at R&D
-fixed the cult shoe sprite not covering a certain pixel. a perfectionist? me?
-office seats facing north now use an overlay so they don't hide parts of players that they shouldn't technically be hiding. (see pic)
-fixed a sanity check that made observers unable to go accross holy turfs if (ticker.mode == null) not that it should happen normally but hey
-added airlock/multi_tile to the get Flat Icon exception list
-fixed the taxi shuttle consoles showing as unpowered even when they aren't