* Pass ellipsis as a parameter to wp_html_excerpt() instead of appending it manually.
* Consolidate the logic to avoid appending ellipsis if the entire string is shown.
* Show ellipsis after truncated filenames and post titles.

props solarissmoke, bpetty, SergeyBiryukov. fixes #11446.

git-svn-id: http://core.svn.wordpress.org/trunk@24214 1a063a9b-81f0-0310-95a4-ce76da25c4cd