Added 'underscore' as a dependency for daves-wordpress-live-search.js and the minified version

git-svn-id: https://plugins.svn.wordpress.org/daves-wordpress-live-search/trunk@971385 b8457f37-d9ea-0310-8a92-e5e31aec5664
Updated copyright dates

git-svn-id: https://plugins.svn.wordpress.org/daves-wordpress-live-search/trunk@971387 b8457f37-d9ea-0310-8a92-e5e31aec5664