added proper social-media image

Signed-off-by: nakami <wirelessbrain@gmx.de>
minor graphic changes
-swapped gif-version of logo with a new css version
-added logo div in register.php
-made error dialog when attempting to login smaller so that it doesn't overlap with info-box

Signed-off-by: nakami <wirelessbrain@gmx.de>
deleted new lines at end of file

Signed-off-by: nakami <wirelessbrain@gmx.de>