Work on refactoring measurements out of Lesion Tracker package

- Removed AssociatedStudies Collection
- Measurement API is generated from configuration files
- Data exchange methods are defined in configuration

Packages/ohif-viewerbase/lib/instanceClassSpecificViewport.js

@@ -0,0 +1,14 @@
+var instanceClassViewportSettingsFunctions = {};
+getInstanceClassDefaultViewport = function(series, enabledElement, imageId) {
+    var instanceClass = series.sopClassUid;
+
+    if (!instanceClassViewportSettingsFunctions[instanceClass]) {
+        return;
+    }
+
+    return instanceClassViewportSettingsFunctions[instanceClass](series, enabledElement, imageId);
+};
+
+setInstanceClassDefaultViewportFunction = function(instanceClass, fn) {
+    instanceClassViewportSettingsFunctions[instanceClass] = fn;
+};