Property window positions are not saved, each window type must be repositioned

Issue description

I generally like to have my property windows on the left so I can see the screen and click on other buildings without having to take the extra step of closing each window. BUT it's a pain because each building type remembers its own settings, BUT they are not remembered in the save file. So each time I start the game I have to go through the agony of repositioning all the windows as I go. I would love to have a property window that is permanently docked to the left.

Reproduction steps

Behavior is consistent

Game version and build number

v 0.7.5c (b455)

Operating system

Windows

Im playing with 21:9 screen resolution and it also bugs me a lot to move all property windows out of center screen always. Having an option to save last window position for all windows would be great.

Yes I also find myself wasting time every game simply repositioning windows. It would be good if the positions were auto saved in save file.