Add automatic build of libcapnp if it's not detected

buildutils/__init__.py

@@ -0,0 +1,12 @@
+"""utilities for building pyzmq.
+
+Largely adapted from h5py
+"""
+
+from .msg import *
+from .config import *
+from .detect import *
+from .bundle import *
+from .misc import *
+from .patch import *
+from .build import *