[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
Merge pull request #229 from redhatrises/dconf_settings

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