display rescan duration

[mcgillroy]

Numbers are fluctuating widely, sometimes up to 10 folders/sec, but often 2-3. Here's a snippet of the log:

16:43:32.687 Scanning directory Sun Ship
16:43:33.044 Scanning directory The Complete 1961 Village Vanguard Recordings (Disc 3)
16:43:33.093 Scanning directory The Complete 1961 Village Vanguard Recordings (Disc 4 of 4)
16:43:33.366 Scanning directory The Major Works of John Coltrane
16:43:33.717 Scanning directory Transition
16:43:34.069 Scanning directory Giant Steps (Japanese 24 Bit Remaster)
16:43:34.408 Scanning directory Boards of Canada
16:43:34.420 Scanning directory A Few Old Tunes Vol. 2
16:43:36.174 Scanning directory Aquarius 7_
16:43:36.216 Scanning directory Boards of Canada
16:43:36.636 Scanning directory Boc Maxima
16:43:37.829 Scanning directory Demo Tape
16:43:38.574 Scanning directory Geogaddi
16:43:39.788 Scanning directory Hi Scores (EP)
16:43:40.126 Scanning directory In a Beautiful Place Out in the Country
16:43:40.453 Scanning directory music has the right to children
16:43:41.317 Scanning directory Peel Sessions
16:43:41.642 Scanning directory Rarieties and Remixes
16:43:42.264 Scanning directory telephasic workshop
16:43:42.346 Scanning directory The Campfire Headphase
16:43:43.184 Scanning directory Tomorrow's Harvest
16:43:43.743 Scanning directory Twoism
16:43:44.164 Scanning directory Christoph De Babalon
16:43:44.173 Scanning directory Scylla & Charybdis
16:43:44.257 Scanning directory Ott