Merge pull request #521 in SNORT/snort3 from ~MIALTIZE/snort3:openssl to master

Merge pull request #521 in SNORT/snort3 from ~MIALTIZE/snort3:openssl to master

Squashed commit of the following:

commit 96939a313fc3cdd3a8722e6c9815fc2eabedc0e7
Author: Michael Altizer <mialtize@cisco.com>
Date:   Thu Jun 16 16:27:37 2016 -0400

    autotools: Make sure hardening prepoc flags checks fail

commit e166520e51dc2fc566cfb31fc67bc6171bfa6e95
Author: Michael Altizer <mialtize@cisco.com>
Date:   Thu Jun 16 16:27:14 2016 -0400

    cmake: Clean up DAQ/SFBPF detection

commit a906cc3d87ea80498cb54263895f1a36dea6a7cf
Author: Michael Altizer <mialtize@cisco.com>
Date:   Wed Jun 15 19:29:16 2016 -0400

    build: Make OpenSSL a hard dependency