Makefile: create a library containing common, wire and bitcoin objects.

This means we don't have to manually choose what to link against,
which is much of the complexity of our Makefiles: the compiler will
automatically use any object files it needs to link.

We already do this for ccan as libccan.a, now we have libcommon.a.

We don't link against it for *everything*, as some tests require their own
versions.

Notes:
1. I get rid of the weird plugins/test/Makefile2 (accidental commit?)
2. Many tests change due to update-mocks.
3. In some places I added the missing dependency on the Makefile itself, though most are in the next
   patch.

Before:
	Total program size:     221366528
	Total tests size:       364243856

After:
	Total program size:     190733656
	Total tests size:       337880888

Build time from make clean (RUST=0) (includes building external libs):

Before:
	real    0m38.227000-44.245000(41.8222+/-1.6)s
	user    3m2.105000-33.696000(23.1442+/-8.4)s
	sys     0m35.054000-42.269000(39.7231+/-2)s
After:
	real    0m38.944000-40.416000(40.1131+/-0.4)s
	user    3m6.790000-17.159000(15.0571+/-2.8)s
	sys     0m35.304000-37.336000(36.8942+/-0.57)s

Build time after touch config.vars (RUST=0):

Before:
	real    0m18.928000-22.776000(21.5084+/-1.1)s
	user    2m8.613000-36.567000(27.7281+/-7.7)s
	sys     0m20.458000-23.436000(22.3963+/-0.77)s

After:
	real    0m19.831000-21.862000(21.5528+/-0.58)s
	user    2m15.361000-30.731000(28.4798+/-4.4)s
	sys     0m21.056000-22.339000(22.0346+/-0.35)s

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

rusty@rusty-Framework:~/devel/cvs/lightni

hsmd/Makefile

@@ -14,48 +14,13 @@ $(HSMD_OBJS): $(HSMD_HEADERS)
 HSMD_CLIENT_OBJS := \
 	hsmd/hsmd_wiregen.o			\
 	hsmd/hsm_utxo.o				\
-	common/htlc_wire.o
 
 # Make sure these depend on everything.
 ALL_C_SOURCES += $(HSMD_SRC)
 ALL_C_HEADERS += $(HSMD_HEADERS)
 ALL_PROGRAMS += lightningd/lightning_hsmd
 
-# Common source we use.
-HSMD_COMMON_OBJS :=				\
-	common/amount.o				\
-	common/autodata.o			\
-	common/base32.o				\
-	common/bigsize.o			\
-	common/bip32.o				\
-	common/bolt12_id.o			\
-	common/bolt12_merkle.o			\
-	common/channel_id.o			\
-	common/daemon.o				\
-	common/daemon_conn.o			\
-	common/derive_basepoints.o		\
-	common/hash_u5.o			\
-	common/hsm_encryption.o			\
-	common/htlc_wire.o			\
-	common/key_derive.o			\
-	common/lease_rates.o			\
-	common/memleak.o			\
-	common/msg_queue.o			\
-	common/node_id.o			\
-	common/onionreply.o			\
-	common/permute_tx.o			\
-	common/psbt_open.o			\
-	common/pseudorand.o			\
-	common/setup.o				\
-	common/status.o				\
-	common/status_wire.o			\
-	common/status_wiregen.o			\
-	common/subdaemon.o			\
-	common/utils.o				\
-	common/version.o			\
-	common/wireaddr.o
-
-lightningd/lightning_hsmd: $(HSMD_OBJS) $(HSMD_COMMON_OBJS) $(BITCOIN_OBJS) $(WIRE_OBJS)
+lightningd/lightning_hsmd: $(HSMD_OBJS) libcommon.a
 
 check-source: check-hsm-versions