We repositioned crypto libs in 4f0f4bf
d93ccf4 libssh2#1013.

This patch also moves libz accordingly.

Reported-by: Kenneth Davidson
Fixes libssh2#1075
Closes #xxxx

We repositioned crypto libs in 4f0f4bf
via libssh2#941 and subsequently in d4f58f0
from d93ccf4 via libssh2#1013.

This patch also moves libz accordingly, to unbreak certain build
scenarios.

Reported-by: Kenneth Davidson
Fixes libssh2#1075
Closes #xxxx

We repositioned crypto libs in 4f0f4bf
via #941 and subsequently in d4f58f0
from d93ccf4 via #1013.

This patch moves libz accordingly, to unbreak certain build scenarios.

Reported-by: Kenneth Davidson
Regression from 4f0f4bf #941
Fixes #1075
Closes #1077

We repositioned crypto libs in 4f0f4bf
via libssh2#941 and subsequently in d4f58f0
from d93ccf4 via libssh2#1013.

This patch moves libz accordingly, to unbreak certain build scenarios.

Reported-by: Kenneth Davidson
Regression from 4f0f4bf libssh2#941
Fixes libssh2#1075
Closes libssh2#1077

Add macOS CI jobs, both cmake and autotools for all supported crypto
backends (except BoringSSL), with debug, zlib enabled. Without running
tests. It also introduces OpenSSL 1.1 into the CI with a non-MSVC
compiler.

Credits to curl's `macos.yml`, that I used as a base.

Fix these issues uncovered by the new tests:

- openssl: fix warning when built with wolfSSL, or OpenSSL 1.1 and
  earlier. CI missed it because apparently the only OpenSSL 1.1 test
  we had used MSVC, which did not complain.

  ```
  ../src/openssl.c:3852:19: error: variable 'sslError' set but not used [-Werror,-Wunused-but-set-variable]
      unsigned long sslError;
                    ^
  ```

  Regression from 097c8f0

- pem: add hack to build without MD5 crypto-backend support.

  The Homebrew wolfSSL build comes with MD5 support disabled. We can
  expect this becoming the norm. FIPS also requires MD5 disabled.

  We deleted the same hack from `hostkey.c` a month ago:
  ad6aae3

  A better fix would be to guard the MD5 logic with our `LIBSSH2_MD5`
  macro.

  ```
  pem.c:214:32: error: use of undeclared identifier 'MD5_DIGEST_LENGTH'; did you mean 'SHA_DIGEST_LENGTH'?
          unsigned char secret[2*MD5_DIGEST_LENGTH];
                                 ^~~~~~~~~~~~~~~~~
                                 SHA_DIGEST_LENGTH
  ```

  Regression from 386e012

- `configure.ac`: add crypto libs late.

  Fix it by adding crypto libs to `LIBS` at the end of the configuration
  process.

  Otherwise `configure` links crypto libs while doing feature tests,
  which can cause unwanted detections. For example LibreSSL publishes
  the function `explicit_bzero()`, which masks the system alternative,
  e.g. `memset_s()` on macOS. Then when trying to compile libssh2, its
  declaration is missing:

  ```
  bcrypt_pbkdf.c:93:5: error: implicit declaration of function 'explicit_bzero' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
      _libssh2_explicit_zero(ciphertext, sizeof(ciphertext));
      ^
  ../src/misc.h:50:43: note: expanded from macro '_libssh2_explicit_zero'
                                            ^
  ```

  Regression from 4f0f4bf

- cmake: fix to list our own include directory before the crypto libs',
  when building tests.

  Otherwise a global crypto header path, such as `/usr/local/include`,
  containing an external `libssh2.h` of a different version, could cause
  weird errors:

  ```
  cc -DHAVE_CONFIG_H -DLIBSSH2_LIBGCRYPT \
    -I../src -I../../src -I/usr/local/include -I[...]/libssh2/include \
    -g -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk  \
    -mmacosx-version-min=12.6 -MD -MT  \
    tests/CMakeFiles/test_aa_warmup.dir/test_aa_warmup.c.o \
    -MF CMakeFiles/test_aa_warmup.dir/test_aa_warmup.c.o.d  \
    -o CMakeFiles/test_aa_warmup.dir/test_aa_warmup.c.o -c \
    [...]/libssh2/tests/test_aa_warmup.c
  ```

  ```
  [ 62%] Building C object tests/CMakeFiles/test_aa_warmup.dir/test_aa_warmup.c.o
  In file included from /Users/runner/work/libssh2/libssh2/tests/test_aa_warmup.c:4:
  In file included from /Users/runner/work/libssh2/libssh2/tests/runner.h:42:
  In file included from /Users/runner/work/libssh2/libssh2/tests/session_fixture.h:43:
  /Users/runner/work/libssh2/libssh2/tests/../src/libssh2_priv.h:649:5: error: type name requires a specifier or qualifier
      LIBSSH2_AUTHAGENT_FUNC((*authagent));
      ^
  /Users/runner/work/libssh2/libssh2/tests/../src/libssh2_priv.h:649:30: error: type specifier missing, defaults to 'int' [-Werror,-Wimplicit-int]
      LIBSSH2_AUTHAGENT_FUNC((*authagent));
                               ^
  /Users/runner/work/libssh2/libssh2/tests/../src/libssh2_priv.h:650:5: error: type name requires a specifier or qualifier
      LIBSSH2_ADD_IDENTITIES_FUNC((*addLocalIdentities));
      ^
  /Users/runner/work/libssh2/libssh2/tests/../src/libssh2_priv.h:650:35: error: type specifier missing, defaults to 'int' [-Werror,-Wimplicit-int]
      LIBSSH2_ADD_IDENTITIES_FUNC((*addLocalIdentities));
                                    ^
  /Users/runner/work/libssh2/libssh2/tests/../src/libssh2_priv.h:651:5: error: type name requires a specifier or qualifier
      LIBSSH2_AUTHAGENT_SIGN_FUNC((*agentSignCallback));
      ^
  /Users/runner/work/libssh2/libssh2/tests/../src/libssh2_priv.h:651:35: error: type specifier missing, defaults to 'int' [-Werror,-Wimplicit-int]
      LIBSSH2_AUTHAGENT_SIGN_FUNC((*agentSignCallback));
                                    ^
  6 errors generated.
  ```

- `tests/session_fixture.h`: delete duplicate `libssh2.h`,
  `libssh2_priv.h` already includes it.

  Follow-up to a683133

CI logs with these errors:
https://github.com/libssh2/libssh2/actions/runs/4824079094
https://github.com/libssh2/libssh2/actions/runs/4824270819

curl's `macos.yml`: https://github.com/curl/curl/blob/da2470de96e94e1c8d276b9ae6e4c97c2cf54239/.github/workflows/macos.yml

Tidying-up while here:

- tests/session_fixture.h: delete duplicate `libssh2.h`.
  `libssh2_priv.h` includes it already.

  Follow-up to a683133

- ci.yml: yamllint warnings and formatting.

- ci.yml: msvc section formatting and step-naming sync with macOS.

  Follow-up to f4a4c05

- ci.yml: enable `--enable-werror` for msys2 jobs.

  Follow-up to 71cae94

- appveyor.yml: show OpenSSL versions, link to image content.

Closes libssh2#1013

We repositioned crypto libs in 4f0f4bf
via libssh2#941 and subsequently in d4f58f0
from d93ccf4 via libssh2#1013.

This patch moves libz accordingly, to unbreak certain build scenarios.

Reported-by: Kenneth Davidson
Regression from 4f0f4bf libssh2#941
Fixes libssh2#1075
Closes libssh2#1077