Implemente layer box

* Layers can be added dynamically
* Layers are sorted

TODO:
- implement load and save functions

CMakeLists.txt

@@ -7,9 +7,9 @@ pkg_check_modules(GTK3 REQUIRED gtk+-3.0)
 include_directories(${GLIB_INCLUDE_DIRS} ${GTK3_INCLUDE_DIRS})
 link_directories(${GLIB_LINK_DIRS} ${GTK3_LINK_DIRS})
 configure_file(glade/main.glade glade/main.glade COPYONLY)
+configure_file(glade/layer-widget.glade glade/layer-widget.glade COPYONLY)
 
 project(gds-render)
-add_executable(${PROJECT_NAME} "main.c" "gdsparse.c" "layer-element.c")
-
+add_executable(${PROJECT_NAME} "main.c" "gdsparse.c" "layer-element.c" "layer-selector.c")
 
 target_link_libraries(${PROJECT_NAME} ${GLIB_LDFLAGS} ${GTK3_LDFLAGS} m)