add support to use a NSMutableArray.SubList for Collection.addAll()
as NSMutableArray.SubList extends NSMutableArray count() and size() should return the same number
fix toString for NSMutableArray.SubList
cache date formatters on a per thread basis
resolve some generics warnings
use existing method
use constants and method from FrontBaseTypes

there is already a class that packages the different value types so use it instead. deprecating the old values/method