Fix popularplaces table for edges queries

[c-w]

We query the popularplaces table like this:

    SELECT placeid, mentioncount, centroidlat, centroidlon
    FROM fortis.popularplaces
    WHERE period = ?
    AND periodtype = ?
    AND pipelinekey = ?
    AND externalsourceid = ?
    AND conjunctiontopic1 = ?
    AND conjunctiontopic2 = ?
    AND conjunctiontopic3 = ?
    AND (periodstartdate, periodenddate) <= (?, ?)
    AND (periodstartdate, periodenddate) >= (?, ?)

So we need to jiggle around some of the column keys so that we can query on period{start,end}date.

[jcjimenez]

LGTM