Improve release management

[przemoc]

Please consider improving release management:

• Use tags reflecting released versions of libb2.
  I advise using standard v<VER> style. (So latest one would be v0.98, pointing to commit 60ea749.)
  Then GitHub's tarballs (tar.gz) available in Tags page will be created just like using git archive --format=tar.gz --prefix="<REPONAME>-<VER>/" v<VER>. (So libb2-0.98 for latest one.)
  But if for some reason your official tarballs on blake2.net differ than those generated automatically using this method, then please upload them to the GitHub release too, so blake2.net won't be the only source of them.
• Put all official libb2 tarballs in one place with directory listing enabled.
  Some suggestions: files.blake2.net, blake2.net/files/, blake2.net/dist/.
  It makes automated scanning for new versions much easier.
• Do not include git repository data in libb2 tarballs.
  https://blake2.net/libb2-0.98.tar.gz (614300 bytes, last modified on 2018-02-02 13:04:19 UTC) that is currently available would be much smaller if generated in the standard fashion (~270 KB).
• Make libb2 existence more official.
  Mention it and link to its latest tarball from the blake2.net front web page.
  libb2 is only mentioned in the context of Rust binding created for it.

[QuLogic]

Also, the code uses autotools and (correctly) does not include the generated files in git. However, to limit the need for end users to need autotools, the tarballs should include the generated files (which they currently do not.)

[veorq]

Thanks guys, not much time on my side, trying to find help :-)
https://twitter.com/veorq/status/978538671929462784

[sneves]

I've added 0.98 tag and a degitified make dist release to the releases Github page.

[QuLogic]

Adding a pkg-config file would be useful too (though everything is mostly in a standard location anyway.)

[ThomasWaldmann]

@QuLogic i just added #22 before reading your comment.

on some OSes / dists, stuff is not at standard locations (e.g. nixos, haiku).

also, when wanting to switch to pkg-config as an application which uses some libs, it would be great if all of them supported it, so all stuff can be dealt with in the same way.

[ThomasWaldmann]

@QuLogic can you review/test #23 ?