Plasma airlock & wall slicing fixes

 * Fixes wrong ignite adminlog message when clicking plasma airlock with hand. ( Fixes #5065 )

* Fixes checks during welding of closets, walls, mineral walls, airlocks.
* Simplifying thermite ignition code on walls.
* Fixes being able to move around during deconstruction procedures of rwall(replacing sleep() with do_after()).
* Simplifying code and fixing inconsistency with slicing diamond wall ( weldingtool faster than drill/cutter at slicing diamond wall )