This should help avoid failed IPv6 connections when "localhost" resolves to an IPv6 literal and mongod does not have `net.ipv6}} enabled to listen for IPv6.

This allows the selectDatabase() and selectCollection() to be tested (PHPLIB-144).

If we've learned anything from the legacy driver, it's that options arrays will prove more flexible than nullable, positional arguments in the long run.

The legacy driver would return a comma-delimited list of host:port combinations; however, that would require __toString() to invoke topology discovery on new Manager instances. Returning the URI is less invasive.

See: PHPC-465, HHVM-129

See: PHPC-444, HHVM-117

Versions of MongoDB before 3.0 create a database when dropping the collection of a database that doesn't exist (as is done by the setUp() method).

Options can be passed directly to FindAndModify after any necessary translation/conversion.