Make it build using OpenSSL 1.1.0

Rebased (azat):
- tabs instead of whitespaces
- make openssl-compat.h safe for complex expressions
- do not call sk_SSL_COMP_free() in 1.1 (fixes double free)

TODO:
- clean methods_bufferevent

Refs: #397 (cherry-picked)
(cherry picked from commit 3e9e0a0d)