This patch adds tasks to secure various network-related settings via sysctl. Documentation will be in a follow-on patch. Controls implemented: - RHEL-07-040350 - RHEL-07-040351 - RHEL-07-040380 - RHEL-07-040410 - RHEL-07-040420 - RHEL-07-040421 - RHEL-07-040730 - RHEL-07-040860 Implements: blueprint security-rhel7-stig Change-Id: I35f82165ccb2ea0e17ea32030968b7f33b1a073a