Minor bug reports and suggestions

[DannyBen]

Hi,

I am placing some minor issues in one ticket, I hope it is ok. If several tickets are preferred, I can split.

1. The "Preserve Image Dimension" icon behavior is random between frames on startup. It sometimes starts in the Locked position, and sometimes not. I believe there should be no reason for most users to want it in the unlocked position.
2. When creating a new project, it would be nice to have the Enter key map to the OK button.
3. I wonder if it would be possible to somehow generate a video that loops seamlessly. I would imagine that it could be possible if the last image is also obeying the transition effect (say Fade) and simply fades to the first image.