wrap all library code into namespace if VCMI_LIB_NAMESPACE is defined

preparation for having client and server in a single process

lib/serializer/JsonSerializer.cpp

@@ -12,6 +12,8 @@
 
 #include "../JsonNode.h"
 
+VCMI_LIB_NAMESPACE_BEGIN
+
 JsonSerializer::JsonSerializer(const IInstanceResolver * instanceResolver_, JsonNode & root_):
 	JsonTreeSerializer(instanceResolver_, &root_, true, false)
 {
@@ -185,3 +187,5 @@ void JsonSerializer::writeLICPartBuffer(const std::string & fieldName, const std
 	}
 }
 
+
+VCMI_LIB_NAMESPACE_END