Use custom sort in SpreadsheetExtractionAlgorithm

Author: jazzido

src/main/java/technology/tabula/extractors/SpreadsheetExtractionAlgorithm.java

@@ -241,9 +241,9 @@ public static List<Rectangle> findSpreadsheetsFromCells(List<? extends Rectangle
         int i = 0;
 
         cells = new ArrayList<Rectangle>(new HashSet<Rectangle>(cells));
-        
-        Collections.sort(cells);
-        
+
+        Utils.sort(cells);
+
         for (Rectangle cell: cells) {
             for(Point2D pt: cell.getPoints()) {
                 if (pointSet.contains(pt)) { // shared vertex, remove it