Add Alt+backspace as alias for Ctrl+w

Input handling for "odd" keys in terminal applications is quite...
                                                         terrible.
cc.c: Fix unclean disconnect on timeout

This gets rid of some ugly "TLS connection non-properly terminated"
errors on the other side of the connection.
net.c: Remove "Read error" prefix in network error messages

The error message itself should be descriptive enough.
uit_userlist.c: adjust column widths for IPv6
uit_userlist.c: Save some horizontal screen space