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.

src/mkmap.c

@@ -28,8 +28,10 @@ schar bg_typ;
     register int i, j;
 
     for (i = 1; i < COLNO; i++)
-        for (j = 0; j < ROWNO; j++)
+        for (j = 0; j < ROWNO; j++) {
             levl[i][j].typ = bg_typ;
+            levl[i][j].lit = FALSE;
+        }
 }
 
 STATIC_OVL void