changes to CMake to add headers

Source/ThirdParty/STB/CMakeLists.txt

@@ -29,5 +29,5 @@ set (SOURCE_FILES ${H_FILES})
 
 set (INCLUDE_DIRS ./)
 
-# # Install headers for building the Urho3D library
-# install_header_files (DIRECTORY ./ DESTINATION ${DEST_INCLUDE_DIR}/ThirdParty/STB FILES_MATCHING PATTERN *.h BUILD_TREE_ONLY)  # Note: the trailing slash is significant
+# Install headers for building the Urho3D library
+install_header_files (DIRECTORY ./ DESTINATION ${DEST_INCLUDE_DIR}/ThirdParty/STB FILES_MATCHING PATTERN *.h)  # Note: the trailing slash is significant