add export statement for cmake config

[ksophocleous]

allows dependent project to use find_package(zlib CONFIG)

namespace chosen to be zlib::

so the targets will look like this:

• zlib::zlibstatic
• zlib::zlib

[rcdailey]

Please see my PR (#295). I add a config package that is a bit more flushed out. Let me know if that one is useful to you.

[ksophocleous]

@rcdailey not sure your PR will be accepted due to the removal of zconf.h. I'll keep this one open until your PR is accepted. If yours is merged first, this one is irrelevant and will be closed.

Please make the namespace change zlib::, it would be quite nice to have that.

[rcdailey]

I am trying to get an explanation as to why zconf.h must be in version control. He mentioned "it's explained elsewhere" but did not mention exactly where. If you know, it would be great if you could point me in the right direction so I can understand it.

Also there's a functional reason to use the namespace, I removed it unintentionally but need to add it back. I will be amending my PR with that change plus others once I get more feedback about zconf.h.

Thanks and please do keep an eye out for those changes!

[rickertm]

Pull request #148 also adds target export with version information and matching config file.

[ksophocleous]

I suppose this is outdated by now, I'll close this one