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/word_list.cpp

@@ -17,7 +17,7 @@ WordListWord::WordListWord()
 {}
 
 IMPLEMENT_REFLECTION_NO_SCRIPT(WordListWord) {
-  if (line_below || is_prefix || isGroup() || script || (tag.reading() && tag.isComplex())) {
+  REFLECT_IF_READING_SINGLE_VALUE {
     // complex value
     REFLECT(name);
     REFLECT(line_below);