Expanded file comparator window to be able to compare one file to many

other files. Also, it can now filter to only show IDs that had data
unique to the one file of interest.

This all should make it easier to find data.

filecomparatorwindow.h

@@ -29,16 +29,16 @@ public:
     ~FileComparatorWindow();
 
 private slots:
-    void loadFirstFile();
-    void loadSecondFile();
+    void loadInterestedFile();
+    void loadReferenceFile();
+    void clearReference();
     void saveDetails();
 
 private:
     Ui::FileComparatorWindow *ui;
-    QVector<CANFrame> firstFileFrames;
-    QVector<CANFrame> secondFileFrames;
-    QString firstFilename;
-    QString secondFilename;
+    QVector<CANFrame> interestedFrames;
+    QVector<CANFrame> referenceFrames;
+    QString interestedFilename;
 
     void calculateDetails();
     void showEvent(QShowEvent *);