added weighted average - rScore now uses weighted average

rowers/templates/workoutstats.html

@@ -9,7 +9,9 @@
   <h1>Workout Statistics for {{ workout.name }}</h1>
   <p>
     This is an experimental page which just lists a bunch of statistics for
-    your workout. This page is under rapid development. 
+    your workout. The mean is of a metric is the mean with equal weight for
+    each stroke. The time weighted mean takes into account the stroke
+    duration.
   </p>
   <div class="grid_2 alpha">
     <p>
@@ -55,6 +57,8 @@
     <tbody>
       <tr>
         <td>Mean</td><td>{{ value.mean|floatformat:-2 }}</td>
+      </tr><tr>
+        <td>Time Weighted Mean</td><td> {{ value.wmean|floatformat:-2 }}</td>
       </tr><tr>
         <td>Minimum</td><td>{{ value.min|floatformat:-2 }}</td>
       </tr><tr>