Fix jQuery prop method declaration

jquery/jquery-1.8.d.ts

@@ -349,7 +349,7 @@ interface JQuery {
     html(htmlString: string): JQuery;
     html(): string;
 
-    prop(propertyName: string): bool;
+    prop(propertyName: string): any;
     prop(propertyName: string, value: any): JQuery;
     prop(map: any): JQuery;
     prop(propertyName: string, func: (index: any, oldPropertyValue: any) => any): JQuery;

jquery/jquery-tests.ts

@@ -1133,6 +1133,7 @@ function test_prop() {
     $("input[type='checkbox']").prop({
         disabled: true
     });
+    var title: string = $('option:selected', this).prop('title');
 }
 
 function test_text() {