add geant4 scene and gcompose app

app/gcompose/CMakeLists.txt

@@ -0,0 +1,20 @@
+
+add_executable(gcompose src/main.cpp)
+
+target_include_directories(gcompose PRIVATE 
+    ${SRC_DIR}
+    ${PROJECT_BINARY_DIR}
+    ${Geant4_INCLUDE_DIRS}
+    ${VTK_INCLUDE_DIRS}
+)
+
+target_link_libraries(gcompose
+    mutomCore
+    mutomMath
+    mutomGeant
+    mutomVtk
+    ${Geant4_LIBRARIES}
+    ${VTK_LIBRARIES}
+)
+
+install(TARGETS gcompose RUNTIME DESTINATION bin)