MOCCACAL-3: Use ColorThemes variables for Calendar

 * at least for the background color of the modal popup
MOCCACAL-13: Being able to see an event details by clicking in the 'calendar view'

 * show the calendar details in the model dialog,
   however in the normal layout and without buttons
MOCCACAL-15: Be able to edit an event from the 'calendar view'

 * make edit view aware when shown inline and add necessary parameters
 * UI code able to load and save eit viwe for existing eents
   by reusing code for new events and some flag
 * formatting some code
MOCCACAL-15: Be able to edit an event from the 'calendar view'

 * use base class haler to create buttons
 * fix bugs: missing / wrong parameters, introduces in the previous commit
 * add dummy 'v'-paramter to prevent caching older js
 * some formating, comments, etc
MOCCACAL-66: Remove reading of undefined macro parameters

 * also fixed some missing javascript escape of urls, just in case
 * code style: removed "comma first" formatting
MOCCACAL-66: Remove reading of undefined macro parameters

 * somehow the last commits broke event creation, fixing ...
MOCCACAL-15: Be able to edit an event from the 'calendar view'

* "edit" button should not submit the form (*cough*)
MOCCACAL-13 - event details view

* fix error message handling - reason was almost always empty,
  now at least show generic error message
MOCCACAL-15: Be able to edit an event from the 'calendar view'

* now switching to edit view works for "short urls", too
MOCCACAL-13: Being able to see an event details by clicking in the 'calendar view'

* add view button to event detail dialog (and a stub for the delete button)
* check the proper access rights for displaying the buttons (and the events too)
* add styling to the buttons - though this need a horrible conditional
  to keep it decent in both colibri and flamingo
* bring back the  "back to calendar" link which got lost in a previous commit
  and changed to to link back form the page we came from (which might have been the overview)
MOCCACAL-14: Be able to delete an event from the 'calendar view'
MOCCACAL-24: Use FullCalendar app as dependency

* update styles to new version of FullCalendar, especially the
  "gadget" / dashoard ones
* also need to add some custom flamingo rules for the
  position of the add button, unfortunately