Loading time optimization (#1569)

* On init, rebuild the dictionnary only once

* Fixed first dictionary update to avoid rebuilding multiple times. Commented some very verbose debug logs (should create a new level: UVERBOSE or UTRACE)

* bump version 0.23: added parameters "Mem/LoadVisualLocalFeaturesOnInit", "Mem/FlannIndexSaved", "Kp/SerializeWithChecksum".

* Renamed Mem/FlannIndexSaved to Kp/FlannIndexSaved. Update UI Preferences with new parameters.

* commented some very verbose debug logs

* Warn flann index serialization not implemented on windows

* Warn flann index deserialization not implemented on windows

* Removing some verbose logs

* missing header (win32)

* Added GlobalMap::fullUpdateNeeded() function

* Adding log

* Save flann index even if links changed

* log time to serialize flann index

* Make dictionary modified only after we update

---------

Co-authored-by: Mathieu Labbe <[email protected]>

corelib/src/VisualWord.cpp

@@ -57,7 +57,7 @@ void VisualWord::addRef(int signatureId)
 	}
 	else
 	{
-		_references.insert(std::pair<int, int>(signatureId, 1));
+		_references.insert(_references.end(), std::pair<int, int>(signatureId, 1));
 	}
 	++_totalReferences;
 }