sort profile fields by category, weight, then title and sort users by uid

Currently the profile_csv modules is inconsistent with the way that data is sorted.

Users:
Mostly the users are sorted by UID, though that is a result of the database and not guaranteed to be consistent by the query format.

Profile fields:
In the profile_csv settings page the fields are sorted by category and title, but not weight.
In the output, profile fields are not sorted.

This patch adds a sort to queries on the users to get them in a consistent order and adds sorts by category, then weight, then title for the profile fields.