Added basic Skupiny form

Also:
* renamed RedirectHelper->set/getRedirectMessage() to set/getMessage()
* changed all occurences of users_skupiny to skupiny
* changed DBSkupiny to new format
* changed Settings::$barvy color format from three to six characters
* finished edit/remove connection

Signed-off-by: dradancer <kuba.zarybnicky@post.cz>