Merged the full Windows console restoration branch

My nightmare is over. I hopefully won’t have to deal with Windows for a while now. Summary of what is now fixed/handled on Windows:

• Ctrl+C, Ctrl+Break and Q exits fully recover the terminal’s state

• Ctrl+C and Ctrl+Break don’t leak mouse escape sequences into the next prompt if you terminate while actively dragging a model

• A bunch of other minor Windows or cmd.exe specific quirks

Only thing that isn’t handled (didn’t find a good way to handle it) is task manager “end process”. It kills the program without cleaning up and sometimes freezes the shell.