[keycloak-dev] Fixes for MySQL 5.1

I've added some fixes for MySQL 5.1 to https://github.com/stianst/keycloak/commit/723a50197ce4489c30d1ca3604c0eb... Bill - can I commit this now? Or do you want me to wait until after you've finished (I don't mind merging it once it is)? Basically it doesn't support keys longer than 1000 bytes, which turns out to be varchar 200, not 255 as default. So I've set all id's that are uuid's to 36, and the others to 200 (user username only, and only used as a foreign key in login failures).