Support namespaces / modules in bif. Checkpoint.

(now actually commiting all the files)

This change is actually two-fold:
a) bif's now accept module XYZ; statements and module::ID for
   function, const, event, enum, etc. declartation
b) Added C++-namespaces to variables, functions, etc. that are declared
   in bif but accessed from C++
   This required some (lightweight) re-factoring of the C++ codes.
   Note, event's don't have their own C++ namespace yet, since this
   would require a rather huge re-factoring.

Compiles and passes test suite.
New namespace feature not tested yet.
Documentation to follow.

src/Portmap.cc

@@ -288,7 +288,7 @@ void PortmapperInterp::Event(EventHandlerPtr f, Val* request, int status, Val* r
 		}
 	else
 		{
-		vl->append(new EnumVal(status, BroTypePtr::Enum::rpc_status));
+		vl->append(new EnumVal(status, BifTypePtr::Enum::rpc_status));
 		if ( request )
 			vl->append(request);
 		}