Bug 256799

Version:           unspecified (using Devel) 
OS:                Linux

The calendar currently contains a two step navigation:

1. browse
2. select view mode

This concept has proven to be suboptimal and confusing for the user (e.g. "where can I save a favorite?").

Please integrate these two steps into a single step with the following specification:

### Day view:
- In day view the left hand folder selection widget has to be shown and operationable. 
- Add Month and Year information to the day view (and other views based on this component)

### Event list view:
- In event list view the left hand folder selection widget has to be shown and operationable (according to bulk actions view). 

### Browsing Mode:
- While browsing the user either sees the "event list"- or the the "day"-view on the right hand side. This view is fully operational, in day view the user can change the shown day by swiping.

### Switching views
- Below the "actions" flap we introduce a new flap "View" in which the user can set the current view mode. This flap is available in all views (e.g. month view). The flap only contains the slection of the view. This section is hence removed from the "actions" flap. 
- Ensure that when switching a view the currently shown date is also shown in the new view. Ideally there should always be one day in the current view selected / activated (so the user does not have to do a single click to select  / activate) that day.
- We need to make sure that when a favorite is saved the current view can be recalled when activating the favorite again.

### Actions
- The "actions" flap integrates all the options of two current views. 
- Additionally we need an action "show date..." which opens the date picker widget and lets the current view switch to the selected date.


Reproducible: Always