Prepare _print_friendly_urls for simpletest testing

Misc fixes from the coder module

Minor code documentation fixes

Update Changelog for 6.x-1.0-rc3

* Created a print.tpl.php template file to give site admins control of what node parts this module renders and how the pages are structured. This feature, combined with the custom print stylesheet option, gives max freedom in rendering print friendly pages.

* Generate printer friendly pages for all node types.  Features include the ability to list $node->body URL references at the end of the page, custom print stylesheet and choosing which node elements to display.