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/client/components/basic/loadingText/loadingText.html

@@ -0,0 +1,5 @@
+<template name="loadingText">
+    <div class="loadingTextDiv">
+        Loading... <i class="fa fa-spin fa-circle-o-notch fa-fw"></i>
+    </div>
+</template>

Packages/ohif-viewerbase/client/components/basic/loadingText/loadingText.styl

@@ -0,0 +1,4 @@
+.loadingTextDiv
+  margin: 30px
+  text-align: center
+  font-weight: 300