Fix for Issue #1346: JObjectField doesn't serialize to BSON

[ultramiraculous]

I previously asked for a fix for Issue #1346, but I already had code written for a fix. Let me know if I need to do anything else

[eltimn]

Thanks for the submission. However, there are a couple of problems;

• To convert JValue to DBObject and vice versa, using JObjectParser is necessary to take advantage of lift-json's features
• Instead of changing BsonRecord to check for JValue, it'd be better to add MongoFieldFlavor to JObjectField

I have a branch with these changes and I will be issuing a pull req shortly.

[ultramiraculous]

Cool, thanks for the feedback and the fix.