added email format for the show_files shortcode and updated the hooks example to display thumbnails table.
also made call_user_func safer by buffering and discarding any php warnings after complete. Added tools directory and the CssToInlineStyles class for inlining css in emails.

git-svn-id: https://plugins.svn.wordpress.org/work-the-flow-file-upload/trunk@903220 b8457f37-d9ea-0310-8a92-e5e31aec5664