[orca-list] Go to upper left and lower right corner in orca.

[Anders Holmberg <anders pipkrokodil se>]

Hi!
In brltty when in a console i can use my braillex el 40 s navigation bar feature to go to the first and last 
lines of a window.
It can be done by pressing the navigationbar so that it clicks twice.
However this feature should be implemented into orca or can i define such things myself?
/A