Merge branch 'tokengrid'
Adding non-functional but styled static login page
add LoginHandlerServlet which provides the static HTML for the login page

also do some cleanup in the SearchUI.checkCitation code
redirect to real homepage after login attempt and also store the error message in the session
actually use the new login page
do not show the "you can log in to see more corpora" message by default
open native window instead of redirect, this does not completly work since we don't have any possibility to communicate when the window was closed yet
updated to Vaadin 7.1.0
Merged 'develop'.
using the new push mechanism to update the gui when the login was sucessful
don't crash when the Helper.setUser function is called with a null argument
make the "Cancel" link work
refactored the login process in order to allow the browsers to remember the password
always unset user on re-initialization of the UI and remove the unused LoginWindow
cleanup
reverted the commits containing the new login process
use iframe in Vaadin Window instead of native window
actuall update user information in initialization
avoid possible null pointer exception if not logged in
more nullpointer checks