PROV-540 : Searching range of measurements

PROV-540 : Searching range of measurements

app/lib/core/Search/SearchEngine.php
app/lib/core/Plugins/SearchEngine/SqlSearch.php

Signed-off-by: Gautier Michelin <gm@ideesculture.com>
Merge pull request #45 from ideesculture/master

PROV-540 : Searching range of measurements