LT-117: Add warning icon in study list row and give tip about user when warning icon is hovered if study is in-use by another user

Packages/lesiontracker/both/collections.js

@@ -3,4 +3,5 @@ Studies = new Meteor.Collection('studies');
 Measurements = new Meteor.Collection('measurements');
 ImageMeasurements = new Meteor.Collection('imageMeasurements');
 
-WorklistSubscriptions = ['studies', 'timepoints'];
+WorklistSubscriptions = ['studies', 'timepoints'];
+Reviewers = new Meteor.Collection('reviewers');