add codecRegistry
bug fix
add default codecregistry to mongo
remove unused imports
add docs
\codereview changes
Add database options test
Merge branch 'registry-option' of https://github.com/guoyr/mongo-java-driver into guoyr-registry-option
Merge branch 'guoyr-registry-option' into 3.0.x
Allow count to work with query hints

JAVA-1344
Port DBCollection changes to allow hint to work with count

JAVA-1344