#249 option to send alt+tab to remote from windows client

[David Kogan]

Currently, unable to do alt+tab switching on target
when working in windows env. It would be nice to have a
feature which would capture alt+tab during some
specific condition - for instance, if the vnc client is
maximized, then send alt+tab to the server.
I've seen this done (by Colin Caughie) (attached) where
all alt+tab was captured, but that meant switching back
and forth whenever returning to windows. It was also
based off a very old vnc version, so it would be nice
to have it on something current.

[David Kogan]

VNC Mod for alt+tab by Colin Caughie