code: function(cov){
          cov = window._$blanket;
  
          var sortedFileNames = [];
  
          var totals =[];
  
          for (var filename in cov) {
              if (cov.hasOwnProperty(filename)) {
                  sortedFileNames.push(filename);
              }
          }
  
          sortedFileNames.sort();
  
          for (var i = 0; i < sortedFileNames.length; i++) {
              var thisFile = sortedFileNames[i];
              var data = cov[thisFile];
              var thisTotal= reportFile( data );
              sendMessage("blanket:fileDone", thisTotal, thisFile);
          }
  
          sendMessage("blanket:done");
  
      }
docs: this function is invoked by blanket.js when the coverage data is ready.  it will compute per-file coverage info, and send a message to the parent phantomjs process for each file, which the grunt task will use to report passes & failures.