add sorting of comments and downtimes #5339

* now comments and downtimes are sortable

refs: #5339
whatthecommit: SHIT ===> GOLD
Merge branch 'feature/make-comments-and-downtimes-sortable-5339' into next

Fixes: #5339
add link do online documentation in menu.html

Refs: #6606
whatthecommit: Become a programmer, they said. It'll be fun, they said.
Merge branch 'feature/add-link-to-online-docs-6606' into next

Fixes: #6606