There should be a way for bots to silently download packages

[kvanbere]

At the moment when bots (hayoo, hoogle, scripts, etc) download packages it increases the download count and causes the download count to be useless for lower numbers (<100) in determining the actual number of users.

There should be a way for bots to download packages without increasing the count.

[dcoutts]

Could try filtering on a user agent. That'd also help with search engines.

Patches accepted.

[gbaz]

An upside of #698 is that it would give a way to resolve this.