Example set permissions tab remade using tree xul element

Previous implementation used listbox xul element with combo boxes in
rows. But these comboboxes didn't work. Clicking on them didn't exapnd
them. So new implementation uses tree xul element.
Delete old set permissions code

It was never fully functional and setting permission
will be moved to different tab so it must be rewritten.
Fix calendar properties dialog size
Created "Add permissions for" dialog

Some example data are hardcoded into dialog. There is no
logic yet. Just dead UI.