Support timezone configuration for Interval deserializer.

[gordchen]

Can you support timezone configuration for the interval deserializer?
The default timezone may be not always the best choice when the interval is constructed from the milliseconds, the UTC is prefered in some cases.

[cowtowncoder]

If that is useful and Joda handles it, may be possible. The main challenge is usually backwards compatibility, related to both handling of defaults (information missing), and in actual serialization format used. Contributions always welcome.

[cowtowncoder]

Implemented so that if timezone is specified via @JsonFormat, it will be set as the timezone of resulting Interval object; that is, as the timezone of start and end times.