Use lua for special level files

Game is playable, and should compile on linux and Windows.
Assumes you have a lua 5.3 library available.

Removes level compiler and associated files.
Replaces special level des-files with lua scripts.
Exposes some NetHack internals to lua:
 - des-table with commands to create special levels
 - nh-table with NetHack core commands
 - nhc-table with some constants
 - u-table with some player-specific data (u-struct)
 - selection userdata

Adds some rudimentary tests.

Adds new extended command #wizloadlua to run a specific script,
and #wizloaddes to run a specific level-creation script.

nhlib.lua is loaded for every lua script.

Download and untar lua:
  mkdir lib
  cd lib
  curl -R -O http://www.lua.org/ftp/lua-5.3.5.tar.gz
  tar zxf lua-5.3.5.tar.gz

Then make nethack normally.

sys/unix/Makefile.dat

@@ -19,9 +19,6 @@ all:	$(VARDAT) spec_levs quest_levs dungeon
 ../util/dgn_comp:
 	(cd ../util ; $(MAKE) dgn_comp)
 
-../util/lev_comp:
-	(cd ../util ; $(MAKE) lev_comp)
-
 ../util/tile2x11:
 	(cd ../util ; $(MAKE) tile2x11)
 
@@ -126,39 +123,10 @@ options:	../util/makedefs
 	../util/makedefs -v
 
 
-spec_levs: ../util/lev_comp \
-	bigroom.des castle.des endgame.des gehennom.des knox.des medusa.des \
-	mines.des oracle.des sokoban.des tower.des yendor.des
-	../util/lev_comp bigroom.des
-	../util/lev_comp castle.des
-	../util/lev_comp endgame.des
-	../util/lev_comp gehennom.des
-	../util/lev_comp knox.des
-	../util/lev_comp medusa.des
-	../util/lev_comp mines.des
-	../util/lev_comp oracle.des
-	../util/lev_comp sokoban.des
-	../util/lev_comp tower.des
-	../util/lev_comp yendor.des
+spec_levs:
 	touch spec_levs
 
-quest_levs: ../util/lev_comp \
-	Arch.des Barb.des Caveman.des Healer.des Knight.des Monk.des \
-	Priest.des Ranger.des Rogue.des Samurai.des Tourist.des Valkyrie.des \
-	Wizard.des
-	../util/lev_comp Arch.des
-	../util/lev_comp Barb.des
-	../util/lev_comp Caveman.des
-	../util/lev_comp Healer.des
-	../util/lev_comp Knight.des
-	../util/lev_comp Monk.des
-	../util/lev_comp Priest.des
-	../util/lev_comp Ranger.des
-	../util/lev_comp Rogue.des
-	../util/lev_comp Samurai.des
-	../util/lev_comp Tourist.des
-	../util/lev_comp Valkyrie.des
-	../util/lev_comp Wizard.des
+quest_levs:
 	touch quest_levs
 
 dungeon: dungeon.def ../util/makedefs ../util/dgn_comp