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/data/settings.cpp

@@ -242,8 +242,6 @@ String Settings::settingsFile() {
 }
 
 IMPLEMENT_REFLECTION_NO_SCRIPT(Settings) {
-  REFLECT_ALIAS(300,         "style_settings",         "stylesheet_settings");
-  REFLECT_ALIAS(300, "default_style_settings", "default_stylesheet_settings");
   REFLECT(locale);
   REFLECT(recent_sets);
   REFLECT(default_set_dir);
@@ -264,7 +262,7 @@ IMPLEMENT_REFLECTION_NO_SCRIPT(Settings) {
   #if USE_OLD_STYLE_UPDATE_CHECKER
     REFLECT(updates_url);
   #else
-    REFLECT_IGNORE(306,"updates_url");
+    REFLECT_COMPAT_IGNORE(<306,"updates_url",String);
   #endif
   REFLECT(package_versions_url);
   REFLECT(installer_list_url);