Generalized "ActionPages". To get LikePage for SomePage, now,

Generalized "ActionPages".  To get LikePage for SomePage, now,
instead of:
  index.php/LikePages?page=SomePage
you should do:
  index.php/SomePage?action=LikePages

The net result is basically the same except, the action buttons on
the resulting page will apply to SomePage rather than LikePages.
(This is probably what the user wants.  If someone is viewing the
LikePages for SomePage, and hits the BackLinks button, he's
probably in search of the BackLinks for SomePage, not the
BackLinks for LikePages.)

Also this eliminates the need for ButtonFactory::make*ActionPageButton.

Since there wasn't much left of ButtonFactory after this change,
I moved what was left into class Theme.  Which is where it
probably belongs.

git-svn-id: svn://svn.code.sf.net/p/phpwiki/code/trunk@1651 96ab9672-09ca-45d6-a79d-3d69d39ca109