Added autocompletion for Bash
Fixes: command_available can run 'type'.
'type' is a Bash builtin in most Linux distros. %x expects a command (a file) to run, so fails to run the builtin.
open command in cygwin.
renamed the "write" method to "display" to alleviate confusion.
modified open so that multiple urls can be opened at once
display each sheet in its own line when listing sheets.
This lets you use e.g. XDG base directories, or anything you like.