Smooth camera and unit motion: display positions, camera target smoothing, pan speed setting

lang/de.lang

@@ -225,6 +225,7 @@ set.volume = Effekt-Lautstärke
 set.music = Musik-Lautstärke
 set.mute = Stumm
 set.rotate_speed = Drehgeschwindigkeit
+set.pan_speed = Kamerageschwindigkeit
 set.zoom_speed = Zoomgeschwindigkeit
 set.edge_scroll = Bildschirmrand-Scrollen
 set.invert = Mausdrehung umkehren

lang/en.lang

@@ -226,6 +226,7 @@ set.volume = Sound volume
 set.music = Music volume
 set.mute = Mute
 set.rotate_speed = Rotation speed
+set.pan_speed = Pan speed
 set.zoom_speed = Zoom speed
 set.edge_scroll = Screen edge scrolling
 set.invert = Invert mouse rotation