Initial Commit for Java.util.Date Extension Support + LocalDateTime Unit Test

[Shounaks]

Issue: #48
Providing Support for java.util.Date, via Extensions.

[cowtowncoder]

Technically this is not JAva 8 date/time type... so probably should be in core jr-objects?

But also, it needs to support deserialization from Integer numbers (timestamp).

[cowtowncoder]

Ok, I think this could use refactoring:

1. Not sure if java.util.Date handling should be added here: core jr-objects supports it with timestamp; should not simply overwrite it without configurability
2. No need to add new extension, just extend JacksonJrJavaTimeExtension
3. No need to add new ReaderWriterProvider, just extend JavaTimeReaderWriterProvider

EDIT: ignore this, see my next note.

[cowtowncoder]

Oh shoot. I should have read it more carefully: this ONLY adds textual read/write for java.util.Date. I was hoping more support for Java 8 date/time types.

I think addition of more features would be ok but should be part of same extension (not separate one) and require configuration (by default leaving serialization as timestamp) -- it's ok to accept textual value by default tho.
However, there is then the question of how to specify format used, and how to (re)configure.