[Enhancement][shared/oval][Fedora][RHEL/7] Update gconf OVAL and XCCDF to dconf and GNOME3

- Update gconf RHEL7 XCCDF to dconf settings
- Add dconf OVAL checks for RHEL7
- Add Fedora XCCDF and OVAL support and checks for dconf
[Fedora] Enable screensaver mode blank OVAL check

- Enable blank screensaver OVAL check in XCCDF for Fedora
[Fedora] Update the Fedora guide.xslt
[Enhancement] Add dconf login banner text OVAL checks

- Enable for Fedora and RHEL7
Fix merge conflicts for dconf settings
Merge remote-tracking branch 'upstream/master' into dconf_settings

Conflicts:
	Fedora/input/guide.xslt
	Fedora/input/system/accounts/physical.xml
	RHEL/7/input/checks/templates/packages_installed.csv
Merge remote-tracking branch 'upstream/master' into dconf_settings

Conflicts:
	Fedora/input/guide.xslt
[RHEL/6] Add remediations for requirements /dev/shm to be mounted with nodev, noexec, and nosuid mount options
[RHEL/6] Fix no_unpackaged_sgid_files /bin/cgclassify executable false positive
[RHEL/6] Exclude /home directory itself from scan when checking if user's home
directories are not group-writable or world-readable. Move the check to shared.
[RHEL/7] Add symlink to the shared/ script.
[Fedora] Add session guide chapter & create symlink to shared file_permissions_home_dirs
OVAL check.
[shared] Fix typo in couple of test_attestation's (should be ref_id, not red_id)
[RHEL/6, RHEL/7, Fedora] input/system/accounts/session.xml:
* fix couple of instances of EOL whitespace noise,
* fix two instances (per each file) of multiple spaces after the
sentence end (replace with just one space).
Merge pull request #327 from iankko/rhel6_whitelist_cgclassify_executable

[bugfix] [RHEL/6]  Whitelist /bin/cgclassify executable coming from libcgroup RPM to fix no_unpackaged_sgid_files false positive
[RHEL/6, RHEL/7, shared] Fix 'Uninstall httpd Package' rule & add shared version of remediation for it
Merge pull request #329 from iankko/homedir_perms_no_groupwrite_worldread_fix

[RHEL/6, RHEL/7, Fedora] Homedir perms no groupwrite worldread fix
[RHEL/6, RHEL/7, shared] Fix 'Uninstall dovecot Package' rule & add shared version of remediation for it
Merge pull request #330 from iankko/rhel6_rhel7_remediations_package_httpd_and_dovecot_removed

[RHEL/6, RHEL/7, shared] Fix 'Uninstall httpd & dovecot Package' rules & add (shared) remediations for them
Merge pull request #229 from redhatrises/dconf_settings

[Enhancement][shared/oval][Fedora][RHEL/7] Update gconf OVAL and XCCDF to dconf and GNOME3
[Enhancement] add OVAL check for multiple NTP servers

- Add check to shared directory and enabled for Fedora and RHEL 6 & 7
[RHEL/6] mount_option_dev_shm remediation fixes - quieten the grep calls,
so running the remediation(s) in shell doesn't display side output. Fixes:
https://github.com/OpenSCAP/scap-security-guide/pull/326#issuecomment-62173616