Make cable collision boxes more accurate for cables

Each cable segment is added to the list, meaning you can get close and
snugly with the cables.

src/main/java/dan200/computercraft/shared/common/BlockGeneric.java

@@ -218,6 +218,12 @@ public abstract class BlockGeneric extends Block implements
         return FULL_BLOCK_AABB;
     }
 
+    @Override
+    public AxisAlignedBB getSelectedBoundingBox( IBlockState state, World worldIn, BlockPos pos )
+    {
+        return getBoundingBox( state, worldIn, pos ).offset( pos );
+    }
+
     @Override
     public final AxisAlignedBB getCollisionBoundingBox( IBlockState state, World world, BlockPos pos )
     {