Add and remove users from sysadmin role from the command line

[rgrp]

Need to be able to create (and remove) sysadmins easily (used to be able to do this via ini file but this functionality was removed a while back in authz system reorganization it seems).

Suggest creating a new paster command as first step.

# user identifier = openid (?)
paster sysadmin add {user identifier}
paster sysadmin remove {user identifier}

Suggest this also be added to main CKAN docs.

This should go into metastable as well as default so that it goes into the v1.2 release (can do this via a transplant from one branch to the other)

[pudo]

This has existed for quite a while, but misses documentation. Has been documented in cset:db18a16a5b4d