Allow multiple undo snapshots to be saved in a buffer for later restoration

The 'Multi Undo' plugin can be called from macros or plugins to save the current image for restoration later. The number of saved images is only limited by available memory. Saved image data is associated with the image from which it came, allowing different slices in an Image Stack to be saved and restored independently.

  run("Multi Undo", "Save");  // Save the current active image to the Multi-Undo stack

  run("Multi Undo", "Undo");   // Restore the last saved snapshot (not necessarily the current image)

  run("Multi Undo", "UndoLast");  // Revert the current image to the most recent associated snapshot

There are no known bugs, however this plugin has not been exhaustively tested

• Create a panel listing available saved snapshots, the images with which they are associates, and buttons to save / restore
• Create a toolbar button

• First release: 2008-03-14