Defines in a namespace that can be required

For consistency, all defines are in the ol namespace.  If they are to be moved to another namespace, they need to be requireable.

src/ol/source/wmssource.js

@@ -2,12 +2,6 @@ goog.provide('ol.source.wms');
 goog.provide('ol.source.wms.ServerType');
 
 
-/**
- * @define {string} WMS default version.
- */
-ol.source.wms.DEFAULT_VERSION = '1.3.0';
-
-
 /**
  * @enum {string}
  */