Factorise the SpaceStationType.cpp code to use LuaTable

I had to address some shortcomings of LuaTable (and MSVC users might want to update their project files), but in the end this will probably be helpful for other areas.

The new features of LuaTable are the methods Sub(Key key) and SubVector(), the first of which pushes a subtable onto the stack and returns the corresponding LuaTable object, and the second doing that for every item in the vector part of the table (assuming they're all tables).

I've done nothing fancy with the SpaceStationType.cpp code itself, it's almost a direct translation :-)