SpellCheckComponent must be able to build/load spell check index on startup and commits. With
SOLR-605, SpellCheckComponent can register an event listener for firstSearcher and newSearcher events and rebuild/reload indices as appropriate.
- If index uses a FSDirectory and exists on disk then just reload it or else build it on firstSearcher event.
- If index is built from a Solr field then re-build it on newSearcher event.
This will help avoid having to add QuerySenderListener in configuration and will not force people to issue build on first query.
All this should be configurable so that people who don't want to rebuild on commits should be able to turn this feature off per configured spell checker.