Added ../css/structure/jquery.mobile.button.css to the css metadata

Author: gseguin

js/jquery.mobile.buttonMarkup.js

@@ -1,7 +1,7 @@
 //>>excludeStart("jqmBuildExclude", pragmas.jqmBuildExclude);
 //>>description: For making button-like links.
 //>>label: Buttons
-//>>css: ../css/themes/default/jquery.mobile.theme.css
+//>>css: ../css/themes/default/jquery.mobile.theme.css, ../css/structure/jquery.mobile.button.css
 
 define( [ "jquery", "./jquery.mobile.core", "./jquery.mobile.vmouse" ], function( $ ) {
 //>>excludeEnd("jqmBuildExclude");