Implement tuple deserialization
Updated readme to reflect tuple support
Fixed map deserializing bug

When deserializing to a map of strings, the deserialization would fail if
the value type was not an object type.
v-0.4
Fixed localization issue

Numbers in JSON would be parsed using the system locale. This should have
used an invariant culture instead.
Moved lexer and parser to Internals namespace

Makes it more explicit that these types are not for public consumption