make remember login token also dependent on password to protect against some brute force attacks on this token

Added export.php for contacts app. Works the same way as the one in the calendar app, except there is no UI for it.
Fixed indentation in /index.php

Filled username field when oc_username is set repaired.
Problems with "advanced settings" button in installation wizard fixed.
CSS improved - login and installation now looks more clean.
Request password link removed (email feature not implemented yet).
Database radio button bugs removed.
It is possible to have an empty database password, now ownCloud will support this "security issue".
Ignore Mac OS X ".DSstore" files.
Fade in/out of login button and remember checkbox removed due to some display errors.

Signed-off-by: Florian Pritz <bluewind@xinu.at>

Created the following function:
 - checkLoggedIn
 - checkAdminUser
 - redirectToDefaultPage

Removed global vars are DOCUMENTROOT, SERVERROOT, SUBURI, WEBROOT and CONFIG_DATADIRECTORY

Initial work on resetting forgotten passwords. It works, but still need to email a token to allow reset