Always add quotes like cmd and powershell

[viocha]

I request for an option to consistently include quotes, similar to cmd and PowerShell, instead of using backslashes.

[sio]

I'm not familiar with how cmd/powershell behave when expanding paths and generally I don't consider them to be good design examples.

Regardless, the suggestion seems sound and it may even make bcpp behavior less quirky. If you (or anyone) are willing to work on this, I'm available for code review and for general discussion.