test: refactor test framework to use a rootfs skeleton

Instead of having to create files, and copying them in place for each
test, we move all static test files to a skeleton rootfs.  This makes
it a lot easier to get an overview of how things and how they work.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

test/skel/bin/busybox-x86_64.md5

@@ -0,0 +1 @@
+ea7e2353af0067a926d3e021e504290e  busybox-x86_64

test/skel/bin/slay

@@ -0,0 +1,47 @@
+#!/bin/sh
+
+nm=$1
+
+# shellcheck disable=SC2046
+getpid()
+{
+	initctl status "$1" |awk '/PID :/{ print $3; }'
+}
+
+pid=$(getpid "$nm")
+if [ -f oldpid ]; then
+	oldpid=$(cat oldpid)
+	if [ "$oldpid" = "$pid" ]; then
+		echo "Looks bad, wait for it ..."
+		sleep 3
+		pid=$(getpid "$nm")
+		if [ "$oldpid" = "$pid" ]; then
+			echo "Finit did not deregister old PID $oldpid vs $pid"
+			initctl status "$nm"
+			ps
+			echo "Reloading finit ..."
+			initctl reload
+			sleep 1
+			initctl status "$nm"
+			exit 1
+		fi
+	fi
+fi
+
+if [ "$pid" -le 1 ]; then
+	sleep 3
+	pid=$(getpid "$nm")
+	if [ "$pid" -le 1 ]; then
+		echo "Got a bad PID: $pid, aborting ..."
+		ps
+		sleep 1
+		initctl status "$nm"
+		ps
+		exit 1
+	fi
+fi
+
+echo "$pid" > oldpid
+
+#echo "PID $pid, kill -9 ..."
+kill -9 "$pid"