* Switch pagetemplate hooks to using named parameters.

* Switch pagetemplate hooks to using named parameters.
* Pass a "destpage" parameter to preprocessor and pagetemplate hooks.
  This will be the page that a source page will be part of, which is
  different than the source page for inlined pages.
* Audited all plugins to endure they pass page, destpage to htmllink
  appropriatly. This means inlining of various plugins will not work
  properly, with correct links generated.