Document precise returned object of values_list()

[Malcolm Tredinnick]

At least one group of highly trained Django developers was tripped up by believing my old documentation, instead of inferring that it must have been slightly imprecise because of the section of documentation it was in.

The values_list() call returns a QuerySet subclass that can be evaluated to a list of thingies. It doesn't actually return a list (you can further filter and slice and dice it before retrieving the values). We should fix the slightly inaccurate language to avoid this happening again.

[Malcolm Tredinnick]

(In [12743]) Fixed #11711 -- clarified that ValuesQuerySets are not lists per se.

It rarely hurts to think of the returned result from a values() or
values_list() call as a list, but it's really an iterable and sometimes
the difference matters.

[Karen Tracey]

(In [12953]) [1.1.X] Fixed #11711 -- clarified that ValuesQuerySets are not lists per se.

It rarely hurts to think of the returned result from a values() or
values_list() call as a list, but it's really an iterable and sometimes
the difference matters.

r12743 from trunk.