Factor out AppGLFW base class

The intention here is to get rid of scaffolding in the consumer
application class and allow to focus on the "important bits".

lib/app/CMakeLists.txt

@@ -0,0 +1,36 @@
+set(imgui_DIR ${PROJECT_SOURCE_DIR}/modules/imgui)
+# set(glfw_DIR ${PROJECT_SOURCE_DIR}/modules/glfw)
+
+message(STATUS "IMGUI:\t" ${imgui_DIR})
+# message(STATUS "GLFW:\t" ${glfw_DIR})
+
+# add_directory(${glfw_DIR})
+
+set(PIXELARIUM_TITLE ${CMAKE_PROJECT_NAME})
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/uiresources_app.h.in
+  ${CMAKE_BINARY_DIR}/uiresources_app.h @ONLY)
+
+set(APPLIBSRC
+  AppGLFW.cpp
+  ${imgui_DIR}/imgui.cpp
+  ${imgui_DIR}/imgui_demo.cpp
+  ${imgui_DIR}/imgui_draw.cpp
+  ${imgui_DIR}/imgui_tables.cpp
+  ${imgui_DIR}/imgui_widgets.cpp
+  ${imgui_DIR}/backends/imgui_impl_opengl3.cpp
+  ${imgui_DIR}/backends/imgui_impl_glfw.cpp)
+
+set(APPLIBNAME pixelariumapplicationlib)
+
+add_library(${APPLIBNAME}
+  STATIC ${APPLIBSRC})
+
+target_link_libraries(${APPLIBNAME}
+  PRIVATE pixelariumutilslib)
+
+target_include_directories(${APPLIBNAME}
+  PUBLIC ${CMAKE_BINARY_DIR}
+  PUBLIC ${PROJECT_SOURCE_DIR}/lib
+  PUBLIC ${imgui_DIR}
+  PUBLIC ${imgui_DIR}/backends
+  PUBLIC ${glfw_INCLUDE_DIR})