remove privacy

1. reduce history list spacing

store history as json

1. English translation

2. Use external storage
3. Fix system window inset

1. add stitch mode

1. do not obfuscate Serializable class

2. fix stitch drawing

1. update ui

1. Scale and rotate

1. Speed up auto stitch

2. draggable float button

1. Speed up import

2. Fix auto stitch images with different size
2. Update privacy