Improve verse indexing speed
Improve verse indexing speed

This reduces the time to build TSKe on my machine from 15 minutes to 2.5 minutes (and makes the progress grow more linearly), and is therefore a great time saver when testing :)

The generated index files do not change.
digitalbiblesociety/browserbible-3,digitalbiblesociety/browserbible-3,digitalbiblesociety/browserbible-3