Specification of the DOT source code through a URL parameter

[magjac]

After starting the editor, the text editor contents should be initialized from a URL parameter.

Ideas

• Name name of the URL parameter could for example be: dotSrc, src or graph.
• If the editor is first initialized with the contents from local storage and then from the URL parameter, it will be possible to undo the change if an update was not what the user intended.
• Should a warning be issued when this happens? (Always after the first time).
• If Allow multiple graphs to be stored in the browser's local storage #70 is implemented:
  • The graph specified with the URL parameter can be saved as a separate entry in local storage.
  • If the same graph already exists in local storage, load the saved version.
  • The name of the graph can optionally be specified with a separate URL parameter.