Not just "%", "@", and ":" must be escaped, all delimiters from RFC 3986
must be percent-encoded. Therefore, since "/" must be escaped in
username and password, we can split the URI at the first "/" instead of
the last.
We haven't tested against anything older than MongoDB 2.2
in a long timei, but we've never been explicit about what
versions we actually support. As of this commit we are
no longer testing against MongoDB 2.2 either. MongoDB 2.2
reached EOL in February of 2014.
This change also removes the gssapiServiceName option (deprecated in
PyMongo 2.8), which is replaced by authMechanismProperties=SERVICE_NAME:<service name>.
The term "cluster" is reserved for sharded clusters in MongoDB documentation.
This document should use the term "deployment" to mean any set of one or
more MongoDB servers.
