[PATCH 4/6] [cmd] Add for /f parsingkeyword parsing, add support for skip=

[Dan Kegel]

Jason wrote:

>>It's clearly time to start splitting WCMD_for into several helper functions.
>
> I completely agree, and it was definitely on my radar to do... its really
> ugly code in there (I take responsibility for a lot of that!) as it has
> been a slow incremental increase in what we actually supported... I was
> aiming to get a set of working /f tests before I did such a reshuffle as
> that is the last of the functionality that for was missing (ie I could
> ensure I keep it all working), but will prioritize it if you want it before
> that.

Seems like it makes sense to add as many tests as possible before
refactoring, but if they're messy to submit without also fixing the
problems they find, go ahead and keep them local for now...
just don't forget to submit them asap.

I must say, it's awesome how you're tearing into the cmd problems!
- Dan