Reduce width of edit/delete column in targets
Extend new numbering scheme into subindicator forms

JS is going to have trouble creating rows with the correct IDs, so lets
just number starting from 0
Use the empty formset for subindicators too

ie the formset with ...__prefix__... in the middle.  We hide it (in the
template) and then copy it in the javascript.  Copying bit still needs
to be done.