Fix strpos usage deprecation warning : 2

Author: jcheron

Ajax/common/html/traits/BaseHtmlPropertiesTrait.php

@@ -103,7 +103,7 @@ public function removeProperty($name) {
 
 	public function propertyContains($propertyName, $value) {
 		$values=$this->_self->getProperty($propertyName);
-		if (isset($values)) {
+		if (isset($values) && $value!=null) {
 			return JString::contains($values, $value);
 		}
 		return false;

Ajax/service/JString.php

@@ -3,7 +3,7 @@
 class JString {
 
 	public static function contains($hay,$needle){
-		return strpos("$hay", $needle) !== false;
+		return strpos($hay, "$needle") !== false;
 	}
 	public static function startswith($hay, $needle) {
 		return substr($hay, 0, strlen($needle)) === $needle;