ClientExtensionRegistry never returns null
bug 449487: New Extensibility Concept for Scout 
https://bugs.eclipse.org/bugs/show_bug.cgi?id=449487

Change-Id: I4a6068eaf98498af087fa969799b09fc930479a6
SharedExtensionRegistry testing
NEW - bug 449487: New Extensibility Concept for Scout 
https://bugs.eclipse.org/bugs/show_bug.cgi?id=449487

Change-Id: Idc58491414bfe9393efffd12ab5121441e39905b
inject new fields