database: new table, couple additions

Session table.
index: session verification

Session verification and destroy if illegal.
NOTE: Currently works only on my domain. I was a bit lazy when I did
this, expect a patch coming soon, it will fix that issue with simple
$_SERVER.
theme: disabled outline style

Fudged up when tabbing.
theme: a couple of additions to the theme
index: registration, login, welcome

Will be a separate class in the future!