added test to show bug with custom serialisation and round trip behaviour
removed reset in serialise/deserilise methods to fix round tripping issue
refactored test to not require nodatime
update ServiceStack to 4.0
Isolate JsConfig changes to a specific scope

With ServiceStack.Text 4.0 it's possible to isolate the JsConfig changes
to a scope instance. This commit wraps the serialize and deserialize calls
in the formatter in a scope where we can mess with the JsConfig properties
without affecting others.
remove unused directives that were requiring NodaTime
Merge branch 'CameronAM-round-trip-bug-fix'