Download downloads a remote file to an io.ReadCloser.
Returns an error if filename is empty or if file does not exist.

Namespaces returns a map containing the canonical and localized namespaces
of the site.
Speaking of sites, sites.go is made containing Version() and Namespaces().

All requests will have utf8 forcibly enabled.
Apparently websites such as Nookipedia cannot accept some GET requests
e.g., {"titles":"File:Example.jpg"} where the period is treated as an invalid character.
I know. Insane.
Curiously this doesn't happen in English Wikipedia.
utf8 fixes that bug.