GLI scheduling feature needs updating

[ak19]

Renate wrote in to the mailing list that scheduling had some issues to do with moving building to index.

The cron.pl it generates for her does the following:

1. an incremental-import and a full-buildcol.pl. Perhaps it should be an incremental-import and an incremental-buildcol.pl, both are grouped into incremental-rebuild.pl

2. the cron.pl does not use activate but manually moves the contents of building to index: building/* to index/*

Need to consider whether it's useful to replace this with a line to separately run the activate.pl script with the -incremental flag.