RUBY-596 Implement remove for collection
RUBY-596 Ensure limit is used during remove from collection
Ensure we are returning BSON Documents not Ruby hashes
RUBY-596 Update documents in a collection
RUBY-596 Get count of documents in a collection
RUBY-596 Move count into executable module
RUBY-596 Add distinct to collection view
Merge pull request #466 from mongodb/collection-operations

RUBY-596 Collection operations