Makefiles: fix from-scratch parallel build.

1) Need config.h before wire/gen_ are compiled.
2) The rule to checkout the libbase58 submodule doesn't work, so use the older
   one-depends-on-the-other approach.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

bitcoin/Makefile

@@ -26,9 +26,11 @@ LIBBASE58_SRC := bitcoin/libbase58/base58.c
 # Can't be inside submodule, as that makes git think it's dirty.
 LIBBASE58_OBJS := bitcoin/libbase58.o
 
-# Wildcards here are magic.  See http://stackoverflow.com/questions/2973445/gnu-makefile-rule-generating-a-few-targets-from-a-single-source-file
-bitcoin/libbase58/libbase58.% bitcoin/libbase58/base58.%:
-	git submodule update bitcoin/libbase58/
+# Wildcards trick from http://stackoverflow.com/questions/2973445/gnu-makefile-rule-generating-a-few-targets-from-a-single-source-file doesn't work with no dependency, so instead make one depend on the other:
+$(LIBBASE58_SRC): $(LIBBASE58_HEADERS)
+
+$(LIBBASE58_HEADERS):
+	git submodule update bitcoin/libbase58/ || true
 	[ -f $@ ] || git submodule update --init bitcoin/libbase58/
 
 bitcoin/libbase58.o: bitcoin/libbase58/base58.c

wire/Makefile

@@ -42,8 +42,8 @@ wire/gen_onion_wire.h: $(WIRE_GEN) wire/gen_onion_wire_csv
 wire/gen_onion_wire.c: $(WIRE_GEN) wire/gen_onion_wire_csv
 	$(WIRE_GEN) ${@:.c=.h} onion_type < wire/gen_onion_wire_csv > $@
 
-wire/gen_peer_wire.o: wire/gen_peer_wire.h
-wire/gen_onion_wire.o: wire/gen_onion_wire.h
+wire/gen_peer_wire.o: wire/gen_peer_wire.h $(CCAN_HEADERS)
+wire/gen_onion_wire.o: wire/gen_onion_wire.h $(CCAN_HEADERS)
 
 check-source: $(WIRE_SRC:%=check-src-include-order/%) $(WIRE_HEADERS:%=check-hdr-include-order/%)