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.

dat/Kni-strt.lua

@@ -0,0 +1,102 @@
+-- NetHack 3.6	Knight.des	$NHDT-Date: 1432512784 2015/05/25 00:13:04 $  $NHDT-Branch: master $:$NHDT-Revision: 1.9 $
+--	Copyright (c) 1989 by Jean-Christophe Collet
+--	Copyright (c) 1991,92 by M. Stephenson
+-- NetHack may be freely redistributed.  See license for details.
+--
+--
+--	The "start" level for the quest.
+--
+--	Here you meet your (besieged) class leader, King Arthur
+--	and receive your quest assignment.
+--
+des.level_init({ style = "solidfill", fg = "." });
+
+des.level_flags("mazelevel", "noteleport", "hardfloor")
+-- This is a kludge to init the level as a lit field.
+des.level_init({ style="mines", fg=".", bg=".", smoothed=false, joined=false, lit=1, walled=false })
+
+des.map([[
+..................................................
+.-----......................................-----.
+.|...|......................................|...|.
+.--|+-------------------++-------------------+|--.
+...|...................+..+...................|...
+...|.|-----------------|++|-----------------|.|...
+...|.|.................|..|.........|.......|.|...
+...|.|...\.............+..+.........|.......|.|...
+...|.|.................+..+.........+.......|.|...
+...|.|.................|..|.........|.......|.|...
+...|.|--------------------------------------|.|...
+...|..........................................|...
+.--|+----------------------------------------+|--.
+.|...|......................................|...|.
+.-----......................................-----.
+..................................................
+]]);
+-- Dungeon Description
+des.region(selection.area(00,00,49,15), "lit")
+des.region(selection.area(04,04,45,11), "unlit")
+des.region({ region={06,06,22,09}, lit=1, type="throne", prefilled=1 })
+des.region(selection.area(27,06,43,09), "lit")
+-- Portal arrival point
+des.levregion({ region = {20,14,20,14}, type="branch" })
+-- Stairs
+des.stair("down", 40,7)
+-- Doors
+-- Outside Doors
+des.door("locked",24,03)
+des.door("locked",25,03)
+-- Inside Doors
+des.door("closed",23,04)
+des.door("closed",26,04)
+des.door("locked",24,05)
+des.door("locked",25,05)
+des.door("closed",23,07)
+des.door("closed",26,07)
+des.door("closed",23,08)
+des.door("closed",26,08)
+des.door("closed",36,08)
+-- Watchroom Doors
+des.door("closed",04,03)
+des.door("closed",45,03)
+des.door("closed",04,12)
+des.door("closed",45,12)
+-- King Arthur
+des.monster("King Arthur", 09, 07)
+-- The treasure of King Arthur
+des.object("chest", 09, 07)
+-- knight guards for the watchrooms
+des.monster({ id = "knight", x=04, y=02, peaceful = 1 })
+des.monster({ id = "knight", x=04, y=13, peaceful = 1 })
+des.monster({ id = "knight", x=45, y=02, peaceful = 1 })
+des.monster({ id = "knight", x=45, y=13, peaceful = 1 })
+-- page guards for the audience chamber
+des.monster("page", 16, 06)
+des.monster("page", 18, 06)
+des.monster("page", 20, 06)
+des.monster("page", 16, 09)
+des.monster("page", 18, 09)
+des.monster("page", 20, 09)
+-- Non diggable walls
+des.non_diggable(selection.area(00,00,49,15))
+-- Random traps
+des.trap("sleep gas",24,04)
+des.trap("sleep gas",25,04)
+des.trap()
+des.trap()
+des.trap()
+des.trap()
+-- Monsters on siege duty.
+des.monster({ id = "quasit", x=14, y=00, peaceful=0 })
+des.monster({ id = "quasit", x=16, y=00, peaceful=0 })
+des.monster({ id = "quasit", x=18, y=00, peaceful=0 })
+des.monster({ id = "quasit", x=20, y=00, peaceful=0 })
+des.monster({ id = "quasit", x=22, y=00, peaceful=0 })
+des.monster({ id = "quasit", x=24, y=00, peaceful=0 })
+des.monster({ id = "quasit", x=26, y=00, peaceful=0 })
+des.monster({ id = "quasit", x=28, y=00, peaceful=0 })
+des.monster({ id = "quasit", x=30, y=00, peaceful=0 })
+des.monster({ id = "quasit", x=32, y=00, peaceful=0 })
+des.monster({ id = "quasit", x=34, y=00, peaceful=0 })
+des.monster({ id = "quasit", x=36, y=00, peaceful=0 })
+