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/get_member.cpp

@@ -36,7 +36,7 @@ GetMember::GetMember(const String& name)
   : target_name(name)
 {}
 
-// caused by the pattern: if (!tag.isComplex()) { REFLECT_NAMELESS(stuff) }
+// caused by the pattern: if (!handler.isCompound()) { REFLECT_NAMELESS(stuff) }
 template <> void GetMember::handle(const String& v) {
   throw InternalError(_("GetDefaultMember::handle"));
 }