Cleanup: move remnants of LAYER_WIDGET to gerbview

These are no longer used in Pcbnew.

gerbview/CMakeLists.txt

@@ -8,7 +8,6 @@ add_definitions(-DGERBVIEW)
 
 include_directories( BEFORE ${INC_BEFORE} )
 include_directories(
-    ${CMAKE_SOURCE_DIR}/pcbnew
     dialogs
     ${CMAKE_SOURCE_DIR}/common
     ${CMAKE_SOURCE_DIR}/3d-viewer
@@ -49,6 +48,7 @@ set( GERBVIEW_SRCS
     gerbview_settings.cpp
     gerbview_frame.cpp
     job_file_reader.cpp
+    layer_widget.cpp
     menubar.cpp
     readgerb.cpp
     rs274_read_XY_and_IJ_coordinates.cpp
@@ -73,7 +73,6 @@ set( GERBVIEW_EXTRA_SRCS
     ${CMAKE_SOURCE_DIR}/common/eda_text.cpp
     ${CMAKE_SOURCE_DIR}/common/widgets/layer_box_selector.cpp
     ${CMAKE_SOURCE_DIR}/common/lset.cpp
-    ${CMAKE_SOURCE_DIR}/pcbnew/layer_widget.cpp
     ${CMAKE_SOURCE_DIR}/common/page_info.cpp
 )
 

pcbnew/pcb_base_edit_frame.cpp

@@ -37,7 +37,6 @@
 #include <dialogs/dialog_grid_settings.h>
 #include <widgets/appearance_controls.h>
 #include <dialogs/eda_view_switcher.h>
-#include <layer_widget.h>
 #include <class_dimension.h>
 #include <wildcards_and_files_ext.h>
 

pcbnew/pcb_edit_frame.h

@@ -437,7 +437,7 @@ public:
     /**
      * Function SetActiveLayer
      * will change the currently active layer to \a aLayer and also
-     * update the PCB_LAYER_WIDGET.
+     * update the APPEARANCE_CONTROLS.
      */
     void SetActiveLayer( PCB_LAYER_ID aLayer ) override;