[PicForth] PicForth versioning

[Jamie Lawson]

Hi Samuel,

Could you add some kind of version indication to at least the picforth.fs
file?

With all these very welcome bug fixes and code additions I have a hard
time keeping the projects based on PicForth up to the standards of the
latest code release.

As I don't get to work on the PicForth projects as much as I would like
to; I therefore end up having several versions in use concurrently.

Regards,
Jamie Lawson