MINOR: ssl: Add ssllib_name_startswith precondition

MINOR: ssl: Add ssllib_name_startswith precondition

This new ssllib_name_startswith precondition check can be used to
distinguish application linked with OpenSSL from the ones linked with
other SSL libraries (LibreSSL or BoringSSL namely). This check takes a
string as input and returns 1 when the SSL library's name starts with
the given string. It is based on the OpenSSL_version function which
returns the same output as the "openssl version" command.