avoid low perf on edition detail (homes)

[anibalpacheco]

• this can be MITIGATED: Make a new dj system check severity warning To avoid low perf on edition detail (homes), or even a timeout result; warn when a single edition has more than K published (also check if having that ammount of non-published ones is a problem too) articles, a default value of k=100 is suggested.
  IMPORTANT: check if this may happen only when the top_position is also equal for that big ammount of articles (I suspect yes)

• or may be SOLVED: the root of the issue may be the list cast in the Edition.top_articles method, if we can keep the resultant QS unevaluated, and of course without breaking any places where used, the problem may dissappear <--- try this option first

Tip for the work: use shell_plus option --print-sql to debug slow SQL