trunk, calendar -> right sidebar should be visible

[trunk] By default, when a user goes to calendar view, there is a search default on user_id. It seems logic but the problem is that by default, he does not see other users in the right sidebar. To see this, he has to clear and search -> it is not intuitive

to test, in a db without demo data :

- create a user with sales user access rights
- as admin, create a meeting (public busy)
- then log you as user and go to meetings view
- by default, the calendar is empty

Problem :
1/ user can't see Administrator meetings.
-> to see it he has to clear and then check the checkbox near customer name

2/ After clearing and selecting the admin user, he is unsable to unselect it... -> works fine if more than 1 user

Solution :
- by default show others user names in the right sidebar (unchecked)
- show meetings of selected users (and don't show other meetings)
- it is working fine in stable version