fix some more session weirdness by deleting loggedin cookies instead of piling them up on top of each other

aaargh, commit flood. I shouldn't leave debugging statements in when committing, I shouldn't leave debugging statements in when commiting, I shouldn't leave ...

timeout anonymous sessions earlier, to stop the session table getting massive. And fix the inevitable stupid bug which crept in

here be a dir to store sql files with database changes which need to be applied to the live site, and the changes required for version 0.3

stop using temporary cookies for logged in users and set a timeout instead. Sessions should now timeout after 48 hours of inactivity, or 8 days since authenticating, whichever comes first. Also fix a bug where we tried to delete users sessions before actually figuring out who they were which stopped logout functioning correctly

from the better-late-than-never department, here's a stupidly overcomplex yet incomplete way of adding new books. Doesn't deal with tagging yet, but better than nothing, don't you think? Maybe someone else should rewrite the whole library component in an afternoon following KISS principles soon ;-)