Fix #1171: Autocompletion not working on Windows

[lolautruche]

Add quotes around the application executable before passing it to the autocomplete hook script.
Quoting prevents issues with the path when containing special characters (WS and/or \).

[pjcdawkins]

The fix might be

• this, or
• Fix autocompletion hook for program paths containing spaces or backslashes #1175 (using --multiple and thus $1 _completion in the hook), and/or
• Escape the program path in the completion command stecman/symfony-console-completion#92 (escaping the path and/or quoting the $1)

[lolautruche]

Not sure what the --multiple option does. I read the description in the original command, but it's still unclear to me.

[pjcdawkins]

The --multiple appears to just change <path> _completion to $1 _completion so if you run platfoo <tab> Bash should be using platfoo as the command name, etc. Which seems convenient, if it works.

[lolautruche]

Thanks for the clarification 👍
Seems handy indeed.