poll: package-specs and version numbers

[Marc Espie <espie@xxxxxxxxx>]

Current documentation says:

The version part starts at the first digit that follows a `-', and
goes on up to the following `-', or to the end of the package name,
if no flavor modifier is present.  It is highly recommended that
all packages have a version number.

I'd like to modify that to make the version number *mandatory*.
In the worst case, an artificial version of 0 would be okay.

The main reason for that is that the current fuzzy spec allows people
to build packages with really weird names, and then they figure out later
that they did it wrong.

With `stronger' specs guarantees, I can add more checks in the
pkg_* code (for package names and for dependency specifications) that
will give out more explicit diagnostics for wrong package names.

Any objections ?