Add comments to helper function

src/app/helpers.coffee

@@ -8,6 +8,9 @@ module.exports.daysBetween = (yesterday, now, dayStart) ->
   
 module.exports.dayMapping = dayMapping = {0:'su',1:'m',2:'t',3:'w',4:'th',5:'f',6:'s',7:'su'}
 
+# http://stackoverflow.com/questions/2532218/pick-random-property-from-a-javascript-object
+# obj: object
+# returns random property (the value)
 module.exports.randomProp = (obj) ->
   result = undefined
   count = 0