winman: when ALT-SHIFT-Q is hit, send a message to the window with focus and let it terminate cleanly
tui: kill and reap child process in Terminal destructor, fix compiler warning
posix: usleep now actually sleeps (rather than converting to seconds and calling sleep()...)
posix: no need for the "don't sleep for under one second" comment anymore, and tweak tv_sec/tv_usec logic slightly
apps: nyancat, via klange (https://github.com/klange/nyancat)