wrap all library code into namespace if VCMI_LIB_NAMESPACE is defined

preparation for having client and server in a single process

lib/mapObjects/CBank.cpp

@@ -1,4 +1,4 @@
-/*
+/*
  * CBank.cpp, part of VCMI engine
  *
  * Authors: listed in file AUTHORS in main folder
@@ -21,6 +21,8 @@
 #include "../IGameCallback.h"
 #include "../CGameState.h"
 
+VCMI_LIB_NAMESPACE_BEGIN
+
 ///helpers
 static std::string & visitedTxt(const bool visited)
 {
@@ -351,3 +353,5 @@ void CBank::blockingDialogAnswered(const CGHeroInstance *hero, ui32 answer) cons
 			doVisit(hero);
 	}
 }
+
+VCMI_LIB_NAMESPACE_END