Update 'Common CKAN Administrator Tasks' docs for 2.0

[seanh]

A few things on this page are out of date, e.g. they refer to the old auth system: http://docs.ckan.org/en/latest/paster.html

Some new paster commands aren't documented.

Should the paster commands docs be pulled from docstrings by autodoc like the api and plugin interfaces docs are? Seems a better way to keep them up to date and not have to write the docs twice

Everything on this page seems to be paster commands, so should the page be renamed CKAN Paster Commands? The current title is a bit generic

This Database Dumps page is also just about a couple of paster commands, so maybe belongs on the same page with the rest of the paster commands now on its own page

[seanh]

@vitorbaptista Assigning this one to you. Can you try and make it pull the docs out of the source using autodoc? This is already done for the plugin interfaces and action API Ask me if you need any guidance. We're hoping to get these done by end of next week so we can release 2.0 in a couple of weeks