Sort events by date if primary sort columnn is the same for both elements

Signed-off-by: Rafał Malinowski <rafal.malinowski@corp.bluecherry.net>
Small cleanup

Signed-off-by: Rafał Malinowski <rafal.malinowski@corp.bluecherry.net>
Merge branch 'fix-147' of github.com:vogel/bluecherry-client into fix-147