use "creature/pkg-active" manage packages manually

- replace "add-pkg-in-pkg-dir" (recursive load-path scanning) with a
  central "creature/pkgs" registry that handles load path, autoloads,
  info dirs and dependencies
- adapt all init-*.el files to the new activation function
- add a top-level Makefile to byte-compile site-lisp packages
- remove unused "emacs-kv" and "emacs-db" submodules

Makefile

@@ -50,9 +50,9 @@ git-modes-clean:
 	$(MAKE) -C $(SITE_LISP)/git-modes clean
 
 emmet-mode:
-	$(MAKE) -C $(SITE_LISP)/emmet-mode emmet-mode.elc
+	$(MAKE) -C $(SITE_LISP)/emmet-mode
 emmet-mode-clean:
-	$(RM) $(SITE_LISP)/emmet-mode/emmet-mode.elc
+	$(MAKE) -C $(SITE_LISP)/emmet-mode clean
 
 expand-region:
 	$(EMACS) -Q --batch  -L $(SITE_LISP)/expand-region -f batch-byte-compile $(SITE_LISP)/expand-region/*.el