build: out-of-tree fixups

Don't glob the leveldb for dist. That means we need to enumerate the headers.

Makefile.am

@@ -47,18 +47,8 @@ COVERAGE_INFO = baseline_filtered_combined.info baseline.info block_test.info \
   leveldb_baseline_filtered.info test_bitcoin_coverage.info test_bitcoin.info
 
 dist-hook:
-	-$(MAKE) -C $(top_distdir)/src/leveldb clean
-	-$(MAKE) -C $(top_distdir)/src/secp256k1 distclean
 	-$(GIT) archive --format=tar HEAD -- src/clientversion.cpp | $(AMTAR) -C $(top_distdir) -xf -
 
-distcheck-hook:
-	$(MKDIR_P) $(top_distdir)/_build/src/leveldb
-	cp -rf $(top_srcdir)/src/leveldb/* $(top_distdir)/_build/src/leveldb/
-	-$(MAKE) -C $(top_distdir)/_build/src/leveldb clean
-
-distcleancheck:
-	@:
-
 $(BITCOIN_WIN_INSTALLER): all-recursive
 	$(MKDIR_P) $(top_builddir)/release
 	STRIPPROG="$(STRIP)" $(INSTALL_STRIP_PROGRAM) $(BITCOIND_BIN) $(top_builddir)/release