document permissions

[utdrmac]

Can you please document what permissions are needed for the user that connects to mongo and runs the tests? The failed auth error messages don't indicate what command failed, and thus it's hard to understand what privs are needed.

[johnlpage]

I run it as Admin as it has to do a bunch of configuration work, can you let me know what error you see. On a sharded cluster it needs to be able to shard collections and presplit and move chunks. It also needs to be able to call serverStatus() to see if it's a sharded cluster.