rtabmap: refining neighbor links uses computeIcpTransform() instead of computeTransform() (to ignore Visual registration, which adds more errors most of the time). When database is in RAM, we can close under a different name than the one used when the database was loaded.

Tango: Added Append Mode option (only start a new map after being localized, default true) and the old map is still shown for convenience until localization. Increased minInliers to 25. Increased ICP correspondenceRatio to 0.5. Decreased time to open a database. Saving doesn't close the database anymore and overwrite only if we save with the same name. Removed ICP refining from standard optimization.

app/android/jni/RTABMapApp.h

@@ -122,6 +122,7 @@ class RTABMapApp : public UEventsHandler {
   void setGridVisible(bool visible);
   void setAutoExposure(bool enabled);
   void setFullResolution(bool enabled);
+  void setAppendMode(bool enabled);
   void setDataRecorderMode(bool enabled);
   void setMaxCloudDepth(float value);
   void setMeshAngleTolerance(float value);
@@ -129,7 +130,7 @@ class RTABMapApp : public UEventsHandler {
   int setMappingParameter(const std::string & key, const std::string & value);
 
   void resetMapping();
-  void save();
+  void save(const std::string & databasePath);
   bool exportMesh(const std::string & filePath);
   int postProcessing(int approach);
 
@@ -154,6 +155,7 @@ class RTABMapApp : public UEventsHandler {
   bool trajectoryMode_;
   bool autoExposure_;
   bool fullResolution_;
+  bool appendMode_;
   float maxCloudDepth_;
   int meshTrianglePix_;
   float meshAngleToleranceDeg_;