Implement account creation

[jimsafley]

Ideally we'd separate account creation (user registration) from the MediaWiki Web interface, but the API does not provide an account creation feature, though it is proposed. Unless there is some other way, all accounts will need to be created via the MediaWiki Web interface.

[jimsafley]

Asking the MediaWiki API mailing list did not result in any helpful suggestions: http://lists.wikimedia.org/pipermail/mediawiki-api/2012-March/002539.html

[jimsafley]

Account creation is now implemented in MW 1.21+:
http://www.mediawiki.org/wiki/API:Account_creation