[ppa-dev] Fix cluster action on Admin page

[Jehan-Guillaume (i. de R. <io...@fr...>]

Hey,

I've commited the Admin page refactoring patch tonight so I could focus
on cluster that was broken in our current dev tree.

Here is a patch which fix it.

Note that I added a function that check if a table has already been
clustered on an index. It allows to disable the cluster button on the
admin page where we are supposed to "recluster" against an already known
index.

Waiting for review and comments, I'll push it in a week or so...