Merge pull request #515 in SNORT/snort3 from ~MIALTIZE/snort3:hardening to master

Merge pull request #515 in SNORT/snort3 from ~MIALTIZE/snort3:hardening to master

Squashed commit of the following:

commit 663bad556621beaea3b22d1880cb3fb7466455f0
Author: Michael Altizer <mialtize@cisco.com>
Date:   Tue Jun 14 16:20:03 2016 -0400

    autotools: Make sure to check headers when searching for OpenSSL crypto support

commit da44da7dcb6872062443484a4a65254a033901fb
Author: Michael Altizer <mialtize@cisco.com>
Date:   Tue Jun 14 14:37:17 2016 -0400

    cmake: Remove unused COMPILE_DEFINITIONS definition during generation.

commit a4da96fc1b6a9a0154bcd7490688f057f81cd158
Author: Michael Altizer <mialtize@cisco.com>
Date:   Mon Jun 13 19:16:42 2016 -0400

    build: Remove PCRE version check - 6.0 was released over 11 years ago

commit 650e05b79e31c66297742dddf3dbf53d4b35d5fa
Author: Michael Altizer <mialtize@cisco.com>
Date:   Mon Jun 13 19:08:37 2016 -0400

    build: Remove useless references to PF_RING libpcap

commit 015daa118d6017d6fef952d4604f50f3c049995a
Author: Michael Altizer <mialtize@cisco.com>
Date:   Mon Jun 13 15:22:39 2016 -0400

    cmake: Clean up OpenSSL libcrypto detection and usage

commit 4e5968d7de913d0dc83ad4cad80dd26d4c60d515
Author: Michael Altizer <mialtize@cisco.com>
Date:   Mon Jun 13 14:53:48 2016 -0400

    cmake: Clean up libpcre detection and fix hints

commit eb9acf119295d91d55b43976710ecf79d397d7a3
Author: Michael Altizer <mialtize@cisco.com>
Date:   Mon Jun 13 14:34:59 2016 -0400

    cmake: Clean up libdnet/libdumbnet detection and fix hints

commit 2e31690d17925123050f1fb05f4be1f12a197ab0
Author: Michael Altizer <mialtize@cisco.com>
Date:   Mon Jun 13 14:18:35 2016 -0400

    cmake: Clean up LuaJIT detection and let it use pkg-config

commit b2700b472758617d3444a4fa35b45d5e4eb85ce3
Author: Michael Altizer <mialtize@cisco.com>
Date:   Mon Jun 13 13:31:00 2016 -0400

    cmake: Add compile-time hardening support and clean up inconsistencies

commit 5192bea466e15ac7c0e127d1af9ff89a6047a775
Author: Michael Altizer <mialtize@cisco.com>
Date:   Mon Jun 13 13:30:41 2016 -0400

    autotools: Add compile-time hardening support