Simplify the `.closest(Array)` code since we no longer use it internally.

It was previously used in liveHandler for delegated events, but is now baked in to events.js. The signature is a strange one since it returns an array of matches, *not* a chainable jQuery object. I've marked it as deprecated.

The code is simplified by two things: 1) We don't care about optimizing the duplicate selectors case, and 2) `.is()` now handles positional selectors by looking for set membership, which eliminates the workaround that was being applied here. See https://github.com/jquery/jquery/commit/70e2e32e0eb03607ad0c8b7752dbd7747da47164 for that commit.

src/traversing.js

@@ -86,35 +86,20 @@ jQuery.fn.extend({
 	closest: function( selectors, context ) {
 		var ret = [], i, l, cur = this[0];
 		
-		// Array
+		// Array (deprecated as of jQuery 1.7)
 		if ( jQuery.isArray( selectors ) ) {
-			var match, selector,
-				matches = {},
-				level = 1;
-
-			if ( cur && selectors.length ) {
-				for ( i = 0, l = selectors.length; i < l; i++ ) {
-					selector = selectors[i];
-
-					if ( !matches[ selector ] ) {
-						matches[ selector ] = POS.test( selector ) ?
-							jQuery( selector, context || this.context ) :
-							selector;
-					}
-				}
+			var level = 1;
 
-				while ( cur && cur.ownerDocument && cur !== context ) {
-					for ( selector in matches ) {
-						match = matches[ selector ];
+			while ( cur && cur.ownerDocument && cur !== context ) {
+				for ( i = 0; i < selectors.length; i++ ) {
 
-						if ( match.jquery ? match.index( cur ) > -1 : jQuery( cur ).is( match ) ) {
-							ret.push({ selector: selector, elem: cur, level: level });
-						}
+					if ( jQuery( cur ).is( selectors[ i ] ) ) {
+						ret.push({ selector: selectors[ i ], elem: cur, level: level });
 					}
-
-					cur = cur.parentNode;
-					level++;
 				}
+
+				cur = cur.parentNode;
+				level++;
 			}
 
 			return ret;