openssl 1.1 support

[The-Compiler]

Running ./configure --with-openssl with openssl 1.1 (which is backwards-incompatible) shows:

checking for OpenSSL version via pkg-config... 1.1.0e found
checking for OpenSSL cflags... 
checking for OpenSSL ldflags... -lssl -lcrypto
checking for openssl/ssl.h... yes
checking for SSL_library_init... no
configure: error: "OpenSSL not found, required for SSL support"

See the full config.log for more details.

[jimklimov]

I wonder if as a short-term solution, we an solicit the old API (whether this works), e.g. from those changelog notes :

* Deprecated interfaces can now be disabled at build time either relative to the latest release via the "no-deprecated" Configure argument, or via the "--api=1.1.0|1.0.0|0.9.8" option.
* Application software can be compiled with -DOPENSSL_API_COMPAT=version to ensure that features deprecated in that version are not exposed.

[The-Compiler]

That sounds like you can opt out of stuff, but probably you won't be able to opt-in to things which were already dropped when building OpenSSL.

[clepple]

@The-Compiler although I haven't had a chance to check, it seems like #504 should help.

[jimklimov]

+1 : See also #504. In fact, does it resolve this issue?..

[The-Compiler]

Sorry for the (very) late answer - I can confirm #504 fixes this. Thanks everyone! Any chance for a new release (v2.7.4 has been released four years ago)?