Migration and upgrade

Hi, sorry for the downtime! The wiki crashed again, so I took the last backup I had and have put it onto an upgraded mediawiki on a new host. Hopefully no more stability issues!

There are a few known issues:

• The backup is only from October last year :( All new users, pages and edits since then are lost, at least for now. Working on this.
• The RumbleStats extension uses deprecated and removed functions in Mediawiki, and the changes I made to at least have it not crash the wiki don't result in it working. If anybody wants to help I'm happy to give server credentials.
• No twitter in the tools sidebar
• Images on the old wiki still broken

On the other hand:

• Upgraded mediawiki
• Emails working again
• New Robocode-specific captcha, so I've re-opened signups.

Anyway, welcome back, and happy Robocoding!