(Breaking this off of SOLR-14597 for independent review)
TypeAsSynonymFilter converts types attributes to a synonym. In some cases the original token may have already had flags set on it and it may be useful to propagate some or all of those flags to the synonym we are generating. This ticket provides that ability and allows the user to specify a bitmask to specify which flags are retained.
Additionally there may be some set of types that should not be converted to synonyms, and this change allows the user to specify a comma separated list of types to ignore (most common case will be to ignore a common default type of 'word' I suspect)