Prevent parsing for plugin - start with TPgSQL for now.

etc/plugins/TSQLServer/P020_TPgSQLServer.C

+class TSQLServer;
+TSQLServer* ROOT_Plugin_TPgSQLServer(const char*,const char*,const char*);
+
 void P020_TPgSQLServer()
 {
    gPluginMgr->AddHandler("TSQLServer", "^pgsql:", "TPgSQLServer",
-      "PgSQL", "TPgSQLServer(const char*,const char*,const char*)");
+      "PgSQL", "::ROOT_Plugin_TPgSQLServer(const char*,const char*,const char*)");
 }

sql/pgsql/src/TPgSQLServer.cxx

@@ -2,7 +2,7 @@
 // Author: g.p.ciceri <gp.ciceri@acm.org> 01/06/2001
 
 /*************************************************************************
- * Copyright (C) 1995-2001, Rene Brun and Fons Rademakers.               *
+ * Copyright (C) 1995-2016, Rene Brun and Fons Rademakers.               *
  * All rights reserved.                                                  *
  *                                                                       *
  * For the licensing terms see $ROOTSYS/LICENSE.                         *
@@ -19,6 +19,14 @@
 #include "TUrl.h"
 #include "TList.h"
 
+////////////////////////////////////////////////////////////////////////////////
+/// PluginManager generator function
+
+TSQLServer* ROOT_Plugin_TPgSQLServer(const char* db, const char* uid, const char* pw) {
+   return new TPgSQLServer(db, uid, pw);
+}
+
+
 ClassImp(TPgSQLServer)
 
 ////////////////////////////////////////////////////////////////////////////////