Should be able to specify no extractor

[perlalien]

Should be able to specify no extractor

[zmughal]

Yes, I'm coming across this now particularly when I am downloading a binary release (.exe, .msi, .pkg) or when I must use a specific extractor plugin (e.g., Extract::CommandLine).

[plicease]

I was able to work around this by using 'f' as the asset "format"
https://metacpan.org/release/PLICEASE/Alien-ghostunnel-0.01/source/alienfile#L43
I still want to make it possible to turn this off in this plugin but I haven't gotten around to doing it yet.

[zmughal]

I still need to run my own extraction code, so I just used an around_hook that does not call the original. Not the best approach but works for now.

[plicease]

#27 should address this. I sort of painted myself into a corner with this one, but with this PR if you set it to none it won't add an extractor, even if you are using the asset mode. I can't think of a situation where you would really not want to extract in tag mode, since that is always a tarball, but no harm I think in having that option even if you never use it.

[plicease]

0.10 should address this!

[plicease]

hopefully we don't ever need to add an extractor called none.