According to the Enumerate Collections Spec, both list_collections and list_collection_names "MUST allow a filter to be passed to include only requested collections".

I noticed this while reviewing https://github.com/mongodb/mongo-python-driver/pull/401. In this PR, we would like to change this line in the docs to use the new list_collection_names:

>>> db.collection_names(include_system_collections=False)
[u'posts']

However, db.list_collection_names() will not have the same behavior because it will include system collections. According to the spec we should support this:

>>> db.list_collection_names(filter={"name": {"$regex": r"^(?!system\.)"}})
[u'posts']

Supporting "filter" will also aid users who are migrating from collection_names to list_collection_names.