patch to PGP 2.6

[cort <cort@ecn.purdue.edu>]

> The only change the future post-September PGP 2.6 messages will have
> is a change in the version number byte from 2 to 3.  PC's little hack
> not to check version numbers will work, but as a patch it's not the
> most robust.  It would be more robust if it checked for the range
> [2..3].

Agreed.

> Another thing a patched 2.3 release would have to do to be fully
> indistinguishable is to generate new version numbers itself after the
> given date.

Is "indistinguishability" the point or "interoperability"?

If the latter, then no change to generated version numbers should
be necessary/desired.  I believe that 2.6 plans to read previous
versions just fine.

Cort.