SCXML Designer should separate qt:editorinfo from the state machine logic when saving

Currently, the <qt:editorinfo> elements are stored as children of the SCXML element they describe. Sometimes many of these <qt:editorinfo> lines change even for for elements the you have not actively clicked and moved.

Mixing the (unstable) visual information with the true SCXML "code" makes it harder to review changes and sometimes almost impossible to merge changes between branches for complex statemachines.

Please consider moving the editorinfo to a separate file or into a separate section in the scxml file.