ClueFocus -> ClueLAT, generate clues for all sp=0 LATs

This e.g. brings 'temperature' clue to 'how hot' query.

We needed however to drop the reliable flag as e.g. 'hot' also gets
converted to 'emotionality', which is not helpful.
AnswerScoreLogistic: Retrained with updated model
CluesMergeByText: Let mergedclue.reliable = any(clues.reliable)

Before, we would inherit the reliable property from the heaviest clue,
but that doesn't really make any sense.
CluesMergeByText subdueInfo(): Add debug info on reliability of merged clues
ClueByTokenConstituent: Mark CluePhrase clues as unreliable

This way, we avoid e.g. ClueSubject phrasal clues being marked reliable.
For proximity queries, all the tokens will seep into them anyway, and we
wouldn't include them in the fulltext search on their own anyway.