add common module as a git submodule
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..3ec196f
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "common"]
+	path = common
+	url = https://git-wip-us.apache.org/repos/asf/ant-antlibs-common.git
diff --git a/common b/common
new file mode 160000
index 0000000..51f7f81
--- /dev/null
+++ b/common
@@ -0,0 +1 @@
+Subproject commit 51f7f81979e31e6ca6d7711c16508a229e940e09