Reduce number of new / delete operations for class KDTreeSearch
Reduce number of new / delete operations for class KDTreeSearch

Add also several TODO comments because it is not clear why expensive
FLOAT64 calculations are used instead of cheaper FLOAT32 ones.

Signed-off-by: Stefan Weil <8d4c780fcfdc41841e5070f4c43da8958ba6aec0@weilnetz.de>

stweil/tesseract,tesseract-ocr/tesseract,UB-Mannheim/tesseract,jbarlow83/tesseract,stweil/tesseract,amitdo/tesseract,amitdo/tesseract,tesseract-ocr/tesseract,tesseract-ocr/tesseract,jbarlow83/tesseract,UB-Mannheim/tesseract,stweil/tesseract,amitdo/tesseract,amitdo/tesseract,UB-Mannheim/tesseract,tesseract-ocr/tesseract,stweil/tesseract,tesseract-ocr/tesseract,jbarlow83/tesseract,jbarlow83/tesseract,UB-Mannheim/tesseract,jbarlow83/tesseract,UB-Mannheim/tesseract,amitdo/tesseract,stweil/tesseract