Implemented new FAQ functionality in help module

install/sql/incremental/upd_0004.sql

install/sql/ispconfig3.sql

interface/web/help/faq_delete.php

interface/web/help/faq_edit.php

interface/web/help/faq_list.php

interface/web/help/faq_sections_delete.php

interface/web/help/faq_sections_edit.php

interface/web/help/faq_sections_list.php

interface/web/help/form/faq.tform.php

interface/web/help/form/faq_sections.tform.php

interface/web/help/lib/lang/cz.lng

interface/web/help/lib/lang/cz_faq_form.lng

interface/web/help/lib/lang/cz_faq_sections_form.lng

interface/web/help/lib/lang/cz_help_faq_sections_list.lng

interface/web/help/lib/lang/en.lng

interface/web/help/lib/lang/en_faq_form.lng

interface/web/help/lib/lang/en_faq_sections_form.lng

interface/web/help/lib/lang/en_help_faq_sections_list.lng

interface/web/help/lib/module.conf.php

interface/web/help/list/faq_list.php