fix & improve docs for *WithWildcards functions
fix & improve docs for *WithWildcards functions

the current docs are very confusing because:
* the terminology of "wildcards" makes people think it adds wildcards to
  the query patterns (prior to looking up data), whereas this does not
  happen.
* the documentation did not describe the relation between "adding
  wildcards" and calling sumSeries, averageSeries, etc.
  Clarify that we form buckets and call the function on each
  bucket.

Also, the example for averageSeriesWithWildcards was effectively
incorrect.

deniszh/graphite-web,deniszh/graphite-web,deniszh/graphite-web,drax68/graphite-web,deniszh/graphite-web,drax68/graphite-web,cbowman0/graphite-web,cbowman0/graphite-web,deniszh/graphite-web,criteo-forks/graphite-web,drax68/graphite-web,graphite-project/graphite-web,graphite-project/graphite-web,criteo-forks/graphite-web,drax68/graphite-web,cbowman0/graphite-web,drax68/graphite-web,criteo-forks/graphite-web,graphite-project/graphite-web,cbowman0/graphite-web,cbowman0/graphite-web,deniszh/graphite-web,criteo-forks/graphite-web,criteo-forks/graphite-web,drax68/graphite-web,criteo-forks/graphite-web,cbowman0/graphite-web,graphite-project/graphite-web,graphite-project/graphite-web,graphite-project/graphite-web