* bookmark.el: Watch bookmark file. Use lexical binding.

* bookmark.el: Watch bookmark file.  Use lexical binding.

(bookmark-watch-bookmark-file): New user variable.
(bookmark-alist): Fix docstring.
(bookmark-bookmarks-timestamp): Renamed from bookmarks-already-loaded.
(bookmark-maybe-load-default-file, bookmark-save, bookmark-load):
Use bookmark-bookmarks-timestamp.
(bookmark-bmenu-mode-map): Define menu bar menu.
(bookmark-show-annotation, bookmark-show-all-annotations):
Make bookmarks buffer read-only.
(bookmark-bmenu-save): Use call-interactively.