- Reuse mixin methods

- Does not need to wait
- Break lines to not extend so much

- When many events are present on same day, a button ("Other##") is created,
  in order to show other events and not break main calendar layout

- Also call wait_for_activities when asked for

- Call wait_ung_calendar_to_load when opening 'calendar' page
- Call wait_ung_listbox_to_load when opening 'ung' page

Because now this dialog is only rendered when user clicks to load it

Url used to get remaining activities

UNG Docs pagination also has an input, where user can enter the
page number he wants to go to. Test that this input also works,
by typing a number than pressing the enter key (code \13).

On UNG Calendar, test for some events that takes more than one day.

Test that on Day and Week view, UNG Calendar defines a red line to
mark current time.