Adds Basic Auth to the Administration Interface

These are some changes that I have made to allow for me to get information from baikal to my application programatically. I will leave it up to you if you would like to merge into the repo. 

"Adds Basic Authentication to the administration interface. It must be forced as it will not be asked for.
This is not I repeat not Basic Authentication for the cal.php etc
interfaces it will only work with /admin/

Also added is a hidden div tag that contains the users id in a tag that
can be id'ed by username_"There Username" this allows you to grab their
ID so that you can add calendars address books etc programatically.

I will confess this is by no way the best way to programatically
manipulate the users but it was the best way that I could do it with
the time I had. A user visiting via the web page will see nothing
different from before."