[#533] Change paster commands docs to follow paster's conventions

In paster's documentation, a required field is shown in UPPER_CASE, and
underscores are used as word separator.
[#533] Update paster's documentation and rename its title
[#533] Remove documentation of paster rights and roles.

They don't exist anymore.
Merge branch '533' of git://github.com/vitorbaptista/ckan into vitorbaptista-533
Merge branch 'vitorbaptista-533'