Per decisions in the previous post:

• Appendix index entries now include all allomorphs.
• Where allomorphs have different feature structures (through <vAlt> elements in the <fs>), the prefixes and suffixes for affixation are now sensitive to those differences and supply the correct versions for each allomorph (this needs rigorous confirmation by ECH).

I've also done a considerable amount of cleanup of the rendering of all indexes, especially the root-based index, which had headwords hanging over into the page margin.

One outstanding question: the root-based index headwords do not include allomorphs right now. I think they probably shouldn't (it's cleaner and clearer without, and in any case you would most likely get to them from the main entries), but if we decide otherwise, all that needs to happen is that code from the fo_extra_indexes.xsl/outputExtraIndexEntry template would need to be imported into the fo_root_based_index.xsl/outputEntry template.