User setup and erlang installation

A bit fiddly, but this lets us run a realistic erlang install script
from userspace, and then re-enter userspace later without wiping the
installation.

debian/mountpoints

@@ -0,0 +1,25 @@
+#!/bin/sh
+
+if test `id -u` -ne 0
+then
+    echo "$0 must be run as root."
+    return
+fi
+
+ROOT=test_environment
+
+check_mount() {
+    if mountpoint "$ROOT$1" > /dev/null
+    then
+        echo "$ROOT$1 already mounted."
+    else
+        mkdir -p "$ROOT$1"
+        mount -o bind "$1" "$ROOT$1"
+    fi
+}
+
+check_mount /proc
+check_mount /sys
+check_mount /dev
+check_mount /dev/pts
+