Added back the missing hash columns in tiki_articles and tiki_submissions. Was...

Added back the missing hash columns in tiki_articles and tiki_submissions. Was removed in r63365 by PhilippeCloutier. Concerning the removal, here's a talk with PhilippeCloutier This pseudo-enhancement was probably intended to be refactoring, but it changed the way the hash columns of tiki_articles and tiki_submissions are handled. Specifically, these columns - which are used by RSS feeds - are no longer set after this commit.

It is not clear whether this was an intentional change. It could have been an accident resulting from an assumption that insertions and updates were equivalent. In reality, insertions dealt with the hash field while updates didn't, at least since 2003-05-16. This was possibly intentional because this hash was used as a permanent identifier so that RSS clients do not load a duplicate of an article when it is edited.

In any case, 4 years later I noticed this "unused" field and removed it in r63365. I missed tiki.sql then, which was fixed by r64820. But I must have had no idea about that field's relation with RSS at that time, and it now turns out that after these 3 commits, the code is still incoherent, as Polyna-Maude indirectly reported in !28 (merged)