annotationView single forward/backward

[bwbohl]

The AnnotationView offers three view modes for annotation participants:

1. grid
2. single
3. list

Using digilib as an image server, when switching to singleView the backward and forward icons to flip through the facsimiles fail to load. Tries to load from /exist/apps/EdiromOnline/pix/annotPreviewForward.png

Using leaflet as an image server, when switching to singleView, loading backwards and forwardPNGs is not even triggered.