Updates to support Environment Canada provider

Code updates to support a new weatherobject element called precipitationUnits. For the 'forecast' and 'hourly' UI, the weather module will use this new element if it is not null (i.e. a provider has pushed some value into this object element). If the element is null, then default 'units' processing will still occur. This allows a provider to have a customn unit of measure for precipitation - e.g. Env Canada will use mm for rain and cm for snow.

modules/default/weather/hourly.njk

@@ -11,6 +11,10 @@
                     {{ hour.temperature | roundValue | unit("temperature") }}
                 </td>
                 {% if config.showPrecipitationAmount %}
+                    <td class="align-right bright precipitation">
+                        {{ hour.precipitation }}{{ hour.precipitationUnits }}
+                    </td>			
+		    {% else %}
                     <td class="align-right bright precipitation">
                         {{ hour.precipitation | unit("precip") }}
                     </td>