Base/App: fix warnings from code analysers:

* convert old-style-casts to explicit C++ casts where possible
* make some implicit conversions explicit

src/App/Enumeration.cpp

@@ -160,7 +160,7 @@ void Enumeration::setEnums(const std::vector<std::string> &values)
     _EnumArray[i] = 0; // null termination
 
     // Other state variables
-    _maxVal = values.size() - 1;
+    _maxVal = static_cast<int>(values.size() - 1);
     _ownEnumArray = true;
     if (_index < 0)
         _index = 0;