Wooden placeholder doors and keys in citadel. SHOCK doors now controllable in scripts and unlockable with correct keys.

More script stuff demystified re repulsors and change type actions. Notes updated in wiki.

Bug fix on texturing flat floors of sloped surfaces getting stretched. 

Updated sample map trunk/samplemaps/shock1.map with version that has lights. Still very experimental and a drag on frame rates. Using lights/tdmnofalloff seems promising on framerate but textures/square looks better and less gridlike.