[kronolith] Remove the personal calendar from the interface

[Sebastian Arcus]

I have a site where all the users share the same calendar for the office 
appointments - and there are no personal/private calendars of any sort. 
The sharing works fine, but I would like to get rid of the personal 
calendar from the interface so that it never gets displayed/enabled by 
mistake and appointments created in the wrong calendar. I've tried 
setting the shared calendar as the default calendar, and deleting the 
personal one - but it always appears back after a logout/login. Is there 
anyway of removing it permanently? They are using the Dynamic interface 
on Firefox 12 on Windows - if it makes any difference.

Sebastian