Added namespacize, to prefix exposed symbols with CCAN_/ccan_.

Current version is a hack: better would be to do decent header analysis 
and not build anything.

ccan_tools/Makefile

@@ -8,6 +8,8 @@ ccan_tools/libtap/src/tap.o:
 ccan_tools/talloc/talloc.o:
 	cd ccan_tools/talloc && ./configure && make
 
+ccan_tools/namespacize: ccan_tools/namespacize.c ccan_tools/talloc/talloc.o
+
 ccan_tools-clean:
 	rm -f run_tests doc_extract
 	@cd ccan_tools/libtap && make clean