Move all of NixOS to nixos/ in preparation of the repository merge

nixos/modules/system/etc/make-etc.sh

@@ -0,0 +1,42 @@
+source $stdenv/setup
+
+mkdir -p $out/etc
+
+set -f
+sources_=($sources)
+targets_=($targets)
+modes_=($modes)
+set +f
+
+for ((i = 0; i < ${#targets_[@]}; i++)); do
+    source="${sources_[$i]}"
+    target="${targets_[$i]}"
+
+    if [[ "$source" =~ '*' ]]; then
+
+        # If the source name contains '*', perform globbing.
+        mkdir -p $out/etc/$target
+        for fn in $source; do
+            ln -s "$fn" $out/etc/$target/
+        done
+
+    else
+        
+        mkdir -p $out/etc/$(dirname $target)
+        if ! [ -e $out/etc/$target ]; then
+            ln -s $source $out/etc/$target
+        else
+            echo "duplicate entry $target -> $source"
+            if test "$(readlink $out/etc/$target)" != "$source"; then
+                echo "mismatched duplicate entry $(readlink $out/etc/$target) <-> $source"
+                exit 1
+            fi
+        fi
+        
+        if test "${modes_[$i]}" != symlink; then
+            echo "${modes_[$i]}" > $out/etc/$target.mode
+        fi
+        
+    fi
+done
+