handling of duplicate namespace declarations
fixed char escaping
fixed xml stream writer indentation
addition QNames
simplified schema location to string method
eReporting Header objects
fixed license headers
eReporting Header encoder
Merge remote-tracking branch 'carsten/feature/eReporting' into feature/eReporting

* carsten/feature/eReporting:
  support for choice settings
fixed schema location string building
fixed NPE while unboxing boolean
hashCode(), equals() and toString() methods
use lists instead of collection to get the concept of equality
use lists instead of collection to get the concept of equality
removed empty default codeSpace to get consistent constructor behaviour

new CodeType("val", null).equals(new CodeType("val")) is now true
transformation function for Nillables
use emptyToNull instead of nullToEmpty
streaming reporting header XML parser
allow generic types
JSON encoders for Java base types