[bugfix][RHEL/7] Fix make warning for RHEL7 builds

- Fixes #318
[Enhancement] [RHEL/6] Enable GUI Warning Banner:
* change OVAL id to start using 'gconf_...' prefix,
* couple of OVAL check cosmetic changes (indentation fixes, test_attestation update etc.),
* change rule ID in XCCDF & profile references to use the OVAL one,
* add remediation
[Enhancement] [RHEL/6] Set GUI Warning Banner Text:
* update OVAL check ID to start using 'gconf_'... prefix,
* couple of OVAL check cosmetic changes (change title & description
  they not to be copied from 'Enable GUI Warning Banner' check, update
  test_attestation etc.),
* change rule ID in XCCDF & profile references to use the OVAL one,
* add remediation
[Enhancement] [RHEL/6] Disable the User List:
* change the OVAL check ID to follow 'gconf_gdm' template,
* couple of OVAL check changes (replace old id with new one, update
  test_attestation etc.),
* change rule ID in XCCDF to use the OVAL one (doesn't seem to be
  referenced in RHEL-6 profiles => no profiles change needed),
* add remediation
Merge pull request #335 from iankko/rhel6_gconf_remediations_round_two

[Enhancement] [RHEL/6] RHEL-6 gconf rule's remediations round two
[Enhancement] move compatible OVAL checks to the shared directory

- Move compatible Fedora checks to the shared directory
- Share no_netrc_files OVAL check and enable for RHEL 6 & 7 and Fedora
- Share securetty OVAL checks and enable for RHEL 6 & 7 and Fedora
- Add Fedora 20 OVAL check
[BugFix] [RHEL/6, RHEL/7, Fedora] Fix & simplify accounts_root_path_dirs_no_write OVAL check. Make it shared.
Merge pull request #339 from iankko/accounts_root_path_dirs_no_write_fix

[BugFix] [RHEL/6, RHEL/7, Fedora] Fix & simplify accounts_root_path_dirs_no_write OVAL check. Make it shared.
[Enhancement] [RHEL/6] Add audit DAC remediations for chmod, fchmod & fchmodat system calls
[Enhancement] [RHEL/6] Add audit DAC remediations for chown group based system calls
                       (chown, fchown, lchown & fchownat)
[Enhancement] [RHEL/6] Add audit DAC remediations for xattr group based system calls
(setxattr, lsetxattr, fsetxattr, removexattr, lremovexattr, and fremovexattr)
Merge pull request #337 from redhatrises/shared_fedora_updates

[Enhancement] move compatible OVAL checks to the shared directory
Merge pull request #340 from iankko/audit_syscall_group_remediations

[Enhancement] [RHEL/6] Add audit syscall remediations for '*chown*, *chmod* & *xattr' groups
Merge pull request #325 from redhatrises/make_warning_rhel7

[bugfix][RHEL/7] Fix make warning for RHEL7 builds. See:
https://github.com/OpenSCAP/scap-security-guide/pull/325#issuecomment-64876450 for reasoning.
[Enhancement] [RHEL/6, RHEL/7] Add remediation for ensure_redhat_gpgkey_installed rule
[BugFix] [RHEL/6, RHEL/7] Fix OVAL check for ensure_redhat_gpgkey_installed rule
[Enhancement] [RHEL/6] Add audit remediations for *time* group based system calls
(adjtimex, settimeofday, and stime). clock_settime case was intentionally left out,
since it will need special care (differently based remediation script).
[BugFix] [RHEL/6] Fix audit_rules_time_stime OVAL check to return appropriate
result also on 64-bit architecture
[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