Auto-loading last file can be problematic

[JansenSmith]

When working with large files, the current behavior of auto-loading the last used file can result in a slog where a new file cannot be loaded until the wrong file completely loads.

Recommended action: load no file and let the user select a file to load or start with a randomly generated filename that does not auto-save until the user modifies something.

[madhephaestus]

start a new doodle, this is intrensic to the file format