adopt some integration suggestions

sys/lib -> sys/libnh
sys/lib/libnethackmain.c -> sys/libnh/libnhmain.c
libnethack.a -> libnh.a

sys/libnh/test/run.sh

@@ -0,0 +1,41 @@
+#!/bin/bash -x
+
+if [ x$1 == "xlib" ]; then
+    echo Doing lib...
+    make spotless
+    cd sys/lib
+    ./setup.sh hints/macOS.2020
+    cd ../..
+    make
+fi
+
+if [ x$1 == "xrunlib" ]; then
+    LIBS="-Lsrc -lnethack -Llib/lua -llua -lm"
+    BADLIBS="-lncurses"
+    rm nhlibtest
+    gcc -o nhlibtest libtest.c $LIBS $BADLIBS
+    ./nhlibtest
+fi
+
+if [ x$1 == "xwasm" ]; then
+    echo Doing wasm...
+    make spotless
+    cd sys/lib
+    ./setup.sh hints/wasm
+    cd ../..
+    make
+fi
+
+if [ x$1 == "xrunwasm" ]; then
+    cd sys/lib/npm-package && node test/test.js
+fi
+
+if [ x$1 == "xbin" ]; then
+    echo Doing bin...
+    make spotless
+    cd sys/unix
+    ./setup.sh hints/macOS.2020
+    cd ../..
+    make
+fi
+