CMake Update

[Mizux]

• Update project() to use VERSION (need CMake >= 3.0)
• Explicit default option for assembly (removed in v1.2.13)
• Use of target_include_directories() instead of include_directories()
• Add ZLIB::ZLIB target alias (to follow FindZLIB.cmake convention)
• Use GNUInstallDirs Module
• Add Export Targets, Config and ConfigVersion cmake file
• Use CTest Module for enable/disable test using BUILD_TESTING
  (note: include(CTest) call enable_testing())

[johnb003]

I'd really like a lot of these changes, is there any problem with these? Perhaps if they were broken into separate pull requests it would be easier to swallow?

[Mizux]

As far as I know, I would say @madler doesn't work (i.e. maintain) anymore this repo so it will be never merge.

5. When you lose interest in a program, your last duty to it is to hand it off to a competent successor.
   The Cathedral and the Bazaar

ps: https://github.com/madler/zlib/pulls?page=1&q=is%3Apr+is%3Aopen+cmake&utf8=%E2%9C%93
29 Open...

[Neustradamus]

@Mizux: Can you rebase your PR?

[Neustradamus]

@madler: I think it is time to look about this?

[Mizux]

@Neustradamus on my way to rebase it... (will also fix ortools patch ^v^ )

[Mizux]

@Neustradamus just rebased to master any feedback welcome...

FYI: upstream macos job are broken
see: 19d7d6b

[Neustradamus]

@Mizux: Thanks for your quick rebase... :)

Have you seen this PR for example?

• Feature/improve cmake #347

There are a lot of:

CMake PRs:

• https://github.com/madler/zlib/pulls?q=is%3Apr+is%3Aopen+cmake

CMake Issues:

• https://github.com/madler/zlib/issues?q=is%3Aissue+is%3Aopen+cmake

cc: @puneetmatharu.

[Mizux]

yes too much, no [cmake] label to flag them.

• Feature/improve cmake #347
  It contains 27 commits and few unrelated stuffs should be split, rebase on master and see what's remain.

Will be better to have a cmake zlib committee, try to submit all PR which already have consensus among cmake users, close duplicates then focus on remaining one to have everything merged or rejected...

[Neustradamus]

@Mizux: Can you rebase your PR?

[madler]

There are too many cmake issues and pull requests for me to go through and disposition them, and I wouldn't know what's good or bad anyway. I very much like @Mizux 's suggestion to have a group render on, coordinate, and most importantly verify proposed cmake changes. My main concern are proposed changes that work in one case, but messes up a bunch of others. Ideally this group would be able to cover a good set of platforms.