independent walking goals finished, scene1 exceptions added

independent walking goals cann now be used by adding the "laufziel"-tag
to szenen.xml representing the targeted position in relative screen
dimensions, see scene 2 picture "knopf" for details. furthermore scene 1
got some exception handling to hide kate during startup before she gets
up.

!!
there still seems to be an error in scene 2 when loaded without scene 1
running before. a dialog is missing when displaying the user privilege
screen and triggers an alert message where this commit changes some code
in dialogControl. the problem persists though, just o highlight it.
!!