Undoing rotation always reverts to 0, instead of the previous value

[shaoshing]

Reproduce:

1. create and select a new layer
2. Set rotation to 10
3. Set rotation to 20
4. undo
5. layer on the canvas is reverted to 10 degree, while the input is set to 0 incorrectly.

[chadrolfs]

This has been the implementation from the beginning. Note too, that if you enter a rotation value, then deselect the shape and then reselect it, it will be reset to 0.

[iwehrman]

@chadrolfs see if this is a dupe? Or consider closing.

[chadrolfs]

1313, #2359

Design Limitation