3rd party implementation of Jackson serializer and deserializer for Quantity

[dmurat]

For my needs, I wrote the Jackson serializer and deserializer for Quantity.
Maybe it may be useful to look it up: croz-ltd/klokwrk-project@c1a6f1f

Code is in Groovy, and tests are in Spock, but this should be easy to follow for Java devs. Any comments about improvements or flaws in implementation are very welcome.

Tnx,
Damir Murat