Unmap the arrow-keys.

  This forces the use of the home-keys.
Merge github.com:skx/dotfiles
Merge github.com:skx/dotfiles
Merge github.com:skx/dotfiles
  IPv4 & IPv6 ping-wrapper.

  This makes it easier to test connectivity than having to remember
 in advance "ping foo.example.com" vs. "ping6 foo.example.com".