[BZ 1138688] - [windows] unable to log in to JON from FF - adding some magic to make the logging in working on newer browsers. Basically, some waiting (20ms) needed to be added before the redirect. Because of the fact that /login and /Coregui.html both uses the same gwt module some logic was added to distinguish between them and prevent the UI from rendering when user is still on the /login page.

(cherry picked from commit 9e915a46d700b5a26777cdc82d83eb8f44b28760)
Signed-off-by: Jirka Kremser <jkremser@redhat.com>