paging 5.x-1.2

Changes since DRUPAL-5--1-1:

• #266373: Adding change that missed last commit: should not be arbitrarily set.
• #179456 by sun: <!--paging_filter--> not removed from HTML output.
• #158782 by sun, Gurpartap Singh: Add 'page' query argument value 'full'.
• #45153 - Do not paginate book module's print page.
• #268608 by sun: Code clean-up.
• #331847 - Check if search module is enabled before updating.
• #266373 by sun with change by me: Add configurable position for pager and should not be arbitrarily set.
• Reverting #266373: $element should not be arbitrarily set.
• #265681 by Gurpartap Singh: Use Drupal 6's node_teaser() for automatic page splitting, which handles the splitting better.
• #194601 by Gurpartap Singh: Ignore blank pages.