Canvas: Remove drawers correctly

Signed-off-by: Jerome Flesch <jflesch@gmail.com>
Frontend: Img Cutting: Handle click-to-zoom

Signed-off-by: Jerome Flesch <jflesch@gmail.com>
Frontend: Img cutting: take into account window resize

Signed-off-by: Jerome Flesch <jflesch@gmail.com>
Canvas: Rearrange some pieces

Signed-off-by: Jerome Flesch <jflesch@gmail.com>