+ * Added support framework for multiple types of dependencies.
+ * Allow declaring that a dependency does not encompass the content of a
+ page. (By passing content => 0 to add_depends.)
+ * pagecount, calendar, postsparkline, progress: Use a contentless dependency,
+ which makes these directives much less expensive to use, since page
+ edits will no longer trigger an unnecessary update.
+ * map: Use a contentless dependency unless show= is specified.
+ This makes simple maps efficient enough that they can be used on sidebars!
+ * inline: Use a contentless dependency in quick mode.