participants-database.php
get_record_id_by_term() changed logic: defaults to single int return value

PDb_Single class
'id' attribute wasn't working, fixed and simplified the code that gets the record data

xnau_FormElement class
simplified handling of checkbox values, also missing "off" value doesn't trigger warning anymore.

CSS: minor edit to participants-database.css

git-svn-id: https://plugins.svn.wordpress.org/participants-database/trunk@817283 b8457f37-d9ea-0310-8a92-e5e31aec5664