[nem-en] ManagerClass.Instance

[vc]

   >macro Manager () {
   >  <[ $(ManagerClass.Instance.MacrosRegistry.GetImplicitCTXName () :
name).Manager ]>
   >}
   
   Use ManagerClass.Instance is bad idea. 
   Sooner or later we shall be obliged to get rid of a similar code.
   It's not re-entrant and not thread safe.
   
   It is possible to replace it with something?