-Upgrade immutable collections package
-Changed blank XML elements to be written as an empty string instead of null
-Added support for XML document type
-Changed string JValue with a null value to be written as null instead of empty string
-Fixed StringEnumConverter thread safety
-Fixed using FloatParseHandling.Decimal with XmlNodeConverter
-Fixed using DateParseHandling.DateTimeOffset with XmlNodeConverter
-Fixed build
-Added support for DateFormatString when reading JSON
-Test
-Fixed type name handling when a property already has a base type assigned
-Fixed build
-Increment version to 6.0.3
-Test
-Rename SpecialPropertyHandling to MetadataPropertyHandling
-Fixed JToken.ReadFrom creating a string value for a comment
-Added JValue.CreateNull and JValue.CreateUndefined
Added Universal App support for Newtonsoft.Json.Portable40.csproj
-Refactor parameterized collection creation to use delegates
Merge pull request #261 from FuUuUuUoO/master

Added Universal App support for Newtonsoft.Json.Portable40.csproj
-Parameterized object creation refactor
-Rename
-Fixed dynamic call method generator to default null value type arguments
-Fixed tests
-More object creation refactoring