Cleaned up the reflection code a bit

* Renamed 'tag' variable to 'handler'
* Removed addAlias stuff, instead check for matching names with if statements
* Added after_reading function that is called by Reader after reading a complete object. This generalizes Packaged::validate, which is now also called via this mechanism.
* Removed some backwards compatibility with <0.3.0 for templates

src/util/io/package.hpp

@@ -255,13 +255,18 @@ class Packaged : public Package {
   virtual Version fileVersion() const = 0;
 
   DECLARE_REFLECTION_VIRTUAL();
-
+  friend void after_reading(Packaged& p, Version file_app_version);
+  
   private:
   bool   fully_loaded;  ///< Is the package fully loaded?
   friend struct JustAsPackageProxy;
   friend class Installer;
 };
 
+inline void after_reading(Packaged& p, Version file_app_version) {
+  p.validate(file_app_version);
+}
+
 // ----------------------------------------------------------------------------- : IncludePackage
 
 /// A package that just contains a bunch of files that are used from other packages