Base: modernize C++11

* remove redundant void-arg
* use nullptr
* replace deprecated headers

src/Base/FileTemplate.cpp

@@ -41,10 +41,10 @@ using namespace Base;
  * A more elaborate description of the constructor.
  */
 ClassTemplate::ClassTemplate()
-  : enumPtr(0)
+  : enumPtr(nullptr)
   , enumVar(TVal1)
   , publicVar(0)
-  , handler(0)
+  , handler(nullptr)
 {
 }