Implementing parser for polymorphic version

[ansharlubis]

1. Added version number to class headers

   class C ver 1 {}

2. Added version variables to the class, method header. It's annotated with reverse angle brackets:

   class C ver 1 >V< {
   >W< m() { ... }
   }

3. Added version arguments for type instances:

   C c = new C>V<();    // version arguments
   new D#W#();          // version binding
   new E#V#>W<();
   c.>V<m();            // method call with version argument