[RHEL/6] Introduce RHEL-6 remediation's functions library to be placed under /usr/share/scap-security-guide/functions location in the package
[RHEL/6] Introduce fix_audit_watch_rule function within that library to be shared / re-used accross audit file system object watch rules
[RHEL/6] Apply the new fix_audit_watch_rule function for audit_time_rules_watch_localtime rule remediation script
[RHEL/6, RHEL/7] "Record Events that Modify User/Group Information" rule - unify XCCDF id with OVAL id (in XCCDFs & also in profile references)
[RHEL/6] Add audit watch remediation for this rule
[BugFix] [Enhancement] [RHEL/6] audit_rules_usergroup_modification OVAL check:
* BugFix       - accept also 'aw', not just 'wa' as permission access type for watch rule,
* Enhancement  - make the check less conservative according to the OVAL check in:
  https://github.com/OpenSCAP/scap-security-guide/blob/master/RHEL/6/input/checks/audit_rules_time_watch_localtime.xml

IOW the check should PASS also in cases the admin wants to audit more strict access type e.g. "rxwa",
than just exactly "wa" (yet IOW the "wa" access type should be minimum / at least type of requirement,
not exact requirement).
[RHEL/6] audit_mac_changes rule:
* Unify XCCDF ID with OVAL ID (in XCCDF & profile references),
* Fix OVAL check:
  - allow 'aw' together with 'wa' in access mode specification
  - also make [aw|wa] minimum requirement, not the exact one
    (IOW allow also stronger audit masks like 'raxw'),
* Add RHEL-6 remediation script.
[RHEL/6] audit_rules_sysadmin_actions rule:
* Unify XCCDF ID with OVAL id (in XCCDF & in profile references),
* Fix OVAL check:
  - to treat 'aw' / 'wa' access type equally,
  - enhance it to make 'wa' / 'aw' minimum requirement (not the exact one) =>
    present permission mask like 'rxwa' would pass too,
* Add RHEL-6 remediation.
Merge pull request #345 from iankko/rhel6_audit_file_system_watch_rules_remediations

[BugFix] [Enhancement] [RHEL/6] audit file system watch rules remediations