Simplify code for tab button

Signed-off-by: Daniel Borchmann <daniel.borchmann@mailbox.tu-dresden.de>
Remove unnecessary dependencies

Signed-off-by: Daniel Borchmann <daniel.borchmann@mailbox.tu-dresden.de>
Use seesaw.util/root-cause

instead of get-root-cause

Signed-off-by: Daniel Borchmann <daniel.borchmann@mailbox.tu-dresden.de>
Reimplement with-swing-error-msg using seesaw.core/dialog

Signed-off-by: Daniel Borchmann <daniel.borchmann@mailbox.tu-dresden.de>
Updating wiki

Signed-off-by: Daniel Borchmann <daniel.borchmann@mailbox.tu-dresden.de>
Working over conexp.contrib.gui.util

again

Signed-off-by: Daniel Borchmann <daniel.borchmann@mailbox.tu-dresden.de>