These issues should be error handled by the GUI

[youralien]

• if the video/aerial image selected in new project creation is no longer there
• if a project of the same name was already created, this should be displayed to the user
• user should be allowed to click "create new project" multiple times in the same session
• if using "Open Camera Image", we should be aware of its path, or copy the image to the /project_dir/{project_name}/homograph/camera.png. Or fix cv2 getting the screenshot of the video (like this issue Camera Image not auto-generated #33)
• if server connection refused
  ... list on going ...