Updated zsh completion patches

[David Bremner]

Vincent Breitmoser <look at my.amazin.horse> writes:

> Hey David,
>
>> I do have one problem with the completion of tags. It seems the
>> treatment of tags with :: in them is not consistent.
>
> Thanks for the hint. I didn't expect :: to be special so I didn't test that
> case. I'll check it out later today or possibly tomorrow.

It is just a convention, but it's used by nmbug, so I guess some people
other than me would hit it.