derekovecs/collocatordb: default order by Log-Dice

I agree with Adam Kilgarriff, Pavel Rychlý and Bryan Jurish. Log-Dice
typically gives a useful score, particulraly for our large corpora. It
neither overemphasizes high frequency collocates (like LLR) nor low
frequency ones (like MI) and does so a little better than MI³, however
not always better than MI².
diff --git a/collocatordb.cc b/collocatordb.cc
index 2fbed98..8234739 100644
--- a/collocatordb.cc
+++ b/collocatordb.cc
@@ -552,6 +552,7 @@
 	bool sortByNpmi(const Collocator &lhs, const Collocator &rhs) { return lhs.npmi > rhs.npmi; }
 	bool sortByLfmd(const Collocator &lhs, const Collocator &rhs) { return lhs.lfmd > rhs.lfmd; }
 	bool sortByLlr(const Collocator &lhs, const Collocator &rhs) { return lhs.llr > rhs.llr; }
+	bool sortByLogDice(const Collocator &lhs, const Collocator &rhs) { return lhs.logdoce > rhs.logdice; }
 
 	std::vector<Collocator> rocksdb::CollocatorDB::get_collocators(uint32_t w1, uint32_t max_w2) {
 		std::vector<Collocator> collocators;
@@ -603,7 +604,7 @@
         right = value;
     }
 
-		sort(collocators.begin(), collocators.end(), sortByLfmd);
+		sort(collocators.begin(), collocators.end(), sortByLogDice);
 		
     /*
     int i=0;