Changed the mining station so that ores will no longer spawn directly…

… on the mine walls. You have to actually do some work to find ores now.

Derelict teleporter now has some more wreckage so that is ia now possible to jump to it from the derelict chapel.
A couple changes to the mining asteroid.

git-svn-id: http://tgstation13.googlecode.com/svn/trunk@2026 316c924e-a436-60f5-8080-3fe189b3f50e