Added 3 methods to MongoTemplate and their declarations to MongoOperations to allow the passing in of an
entity object along with a collection name.  The methods then converts the entity object using registered converters before sending it to the database.

updateMulti(Query query, Object entity, class<?> entityClass, String collectionName)
updateFirst(Query query, Object entity, class<?> entityClass, String collectionName)
upsert(Query query, Object entity, class<?> entityClass, String collectionName)

Created a new class that extends AbstractMongoConfiguration and allows for the creation of a MongoTemplate with custom converters in Java.

/src/main/java/org/springframework/data/mongodb/config/SimpleMongoConfiguration.java

- Chuong Ngo