Add Next/Previous Hanging Protcol stage buttons (only works with MG for now)

Packages/viewerbase/log.js

@@ -1,3 +1,3 @@
 // Create package logger using loglevel
 // https://atmospherejs.com/spacejamio/loglevel
-log = loglevel.createPackageLogger('viewerbase', defaultLevel = 'warn');
+log = loglevel.createPackageLogger('viewerbase', defaultLevel = 'info');