Properly protect macro arguments
This should fix most of those crashes when quitting

Hide window immediately when quitting.
Wait for all clients to call -disconnect before allowing the main loop to terminate.
Ignore all received data when terminating (since our window has been destroyed by then).
remove debug code
Bump.
Merge branch 'v3.0.1' of ssh://gh/winny-/Textual into v3.0.1
Revert "Moved README to README.md and expanded it."

This reverts commit 9af619546cef035819bc4a9fd4ba3e9591ddd49a.