Some terminals send spurious releases for mouse wheel in SGR mouse mode,
this causes confusion when tmux uses SGR outside but the application
inside tmux is using conventional xterm mouse reporting. So suppress
obviously bad input. From Timothy Allen, SF bug 128.
Reset the buttons when the wheel is used, from Balazs Kezes.
Copy newline when at EOL in vi(1) mode, from Balazs Kezes.