Partly solving issue 1490: "Comparator Tab / Light Table / Inspector" with the addition of an "Inspect" tab to the File Browser panel.

rtgui/filebrowserentry.h

@@ -45,6 +45,7 @@ class FileBrowserEntry : public ThumbBrowserEntryBase,
 
     double scale;
     static bool iconsLoaded;
+    bool wasInside;
     ImageAreaToolListener* iatlistener;
     int press_x, press_y, action_x, action_y;
     double rot_deg;