[RHEL/6] audit_network_modifications rule:
* 1) Unify XCCDF ID with OVAL ID in:
     - XCCDF & rule references
* 2) Fix OVAL check:
     - treat 'wa' / 'aw' access modes equally,
     - enhance it to allow stronger masks (like 'rxaw') too
* 3) Add RHEL-6 remediation utilizing the fix_audit_syscall_rule()
     function added in previous commit