Because we are likely to be having more userspace programs soon, and
reproducing manual makefiles is a bad idea, make extensions/ ready
for automake traversal. The build pattern now is:
1. toplevel Makefile.am starts off with extensions/Makefile.am
2. Makefile.am
a. builds programs in current directory
b. runs Kbuild
- only from extensions/Makefile.am
(so it does not get reinvoked from case 2cII)
- Kbuild recurses on its own
c. runs Mbuild
I. builds iptables shared libraries in current directory
II. runs Makefile.am in each subdir (goto step 2.)
