Updating files to output valid HTML5, specifically the leggaro theme.
Changed table class from entrylist to staticlist for ease of styling.
Integrated Piero's widget fix to admin.widgets.default.php.
Wrapped footer implementation in footer tags.
Changed abbr in calendar plugin to class, deprecated element tag.
Spelling and grammar correction in setup lang.en-us.php.

Signed-off-by: liquibyte <liquibyte@gmail.com>