enhancement: save & restore size/position of a session window

[ootada]

• setting aside and restoring session preferably should lose no info on the state of the window (radio receiver-like: turn it off and on and you still hear the same station same way as before)
• should be able to restore size/position on non first/default workspace/display
• should be able to handle display configuration changes (example: having 2 big displays when docked but one smaller laptop screen when undocked)

[tim-we]

I think this would be a great feature but there are some problems. Remembering the position & size and restoring that would not be problem but AFAIK there is no way to detect multiple screens.
I use 2 monitors myself and the only API that I know in regards to this (window.screen) only gives me the width & height of the primary display. Any ideas?