Fix calendar annoyances

A lot of fixes … cc @owncloud/designers @georgehrke 

* simplified the event detail view to focus on title and time
* fixed some layout issues cc @mbiebl, fix https://github.com/owncloud/apps/issues/1482
* remove superfluous tipsy popup which just repeated obvious info
* remove scrolling to switch moth which made the calendar unusable with lots of events, fix #24, fix https://github.com/owncloud/apps/issues/771
* make event detail view and settings view scrollable, fix #81
* color weekend, don’t bold weekday names, lighter border color
* display full share permissions in share tab
* disable half-baked list view, change for proper day view, fix #80 
* fix access class wording, fix #113 
* remove superfluous 'Active' checkbox in edit calendar view
* lots more details


Would be cool if someone of you can fix #185 (loading feedback not visible). That I couldn’t manage.