Add ippool unit-test for 'make check' runs

This test creates a variety of v4 (and one v6) pool and performs
allocations until the pool is full, then frees a random number of
randomly distributed addresses, re-allocates them and again checks that
they're all available and finally once the pool is full allocations
fail.

Change-Id: Ibf4588e8f3ae71684e5262c0caaa2689aee73a94
diff --git a/tests/lib/ippool_test.err b/tests/lib/ippool_test.err
new file mode 100644
index 0000000..7dc5371
--- /dev/null
+++ b/tests/lib/ippool_test.err
@@ -0,0 +1,10 @@
+No more IP addresses available
+No more IP addresses available
+No more IP addresses available
+No more IP addresses available
+No more IP addresses available
+No more IP addresses available
+No more IP addresses available
+No more IP addresses available
+No more IP addresses available
+No more IP addresses available