eliminated some warnings

include/Application.h

@@ -195,6 +195,7 @@ namespace ChimeraTK {
     }
 
     void registerDeviceModule(DeviceModule* deviceModule);
+
    protected:
     friend class Module;
     friend class VariableNetwork;
@@ -391,7 +392,7 @@ namespace ChimeraTK {
                                    "caused by "
                                    "incorrect ownership of variables/accessors or VariableGroups.");
     }
-    void setCurrentVersionNumber(VersionNumber) {
+    void setCurrentVersionNumber(VersionNumber) override {
       throw ChimeraTK::logic_error("setCurrentVersionNumber() called on the application. This is probably "
                                    "caused by "
                                    "incorrect ownership of variables/accessors or VariableGroups.");

include/ApplicationModule.h

@@ -18,7 +18,7 @@ namespace ChimeraTK {
 
   class Application;
   class ModuleGroup;
-  class ConfigReader;
+  struct ConfigReader;
 
   class ApplicationModule : public ModuleImpl {
    public:

include/ModuleImpl.h

@@ -13,7 +13,7 @@
 
 namespace ChimeraTK {
 
-  class ConfigReader;
+  struct ConfigReader;
 
   /**
    *  Some common implementations of a few functions in Module used by most

include/VariableGroup.h

@@ -17,7 +17,7 @@
 namespace ChimeraTK {
 
   class ApplicationModule;
-  class ConfigReader;
+  struct ConfigReader;
 
   class VariableGroup : public ModuleImpl {
    public: