Add Window Dismantling

Enables dismantling of a window (100% return) with a wrench, if the
window is fully unsecured. Windows which cannot be dismantled will
return a message saying so for clarity. Dismantling displays a visible
message for clarity.
Full Window returns stacked glass

Tweaked code to make a full window return a stack of two, rather than
two separate sheets.
Merge pull request #6946 from TwistedAkai/dev

Add Window Dismantling