Gallery

Maybe related to recent changes, we upsample originals
when generating resizes, if the sizelimit module is
enabled.

Steps to reproduce:
1. enable sizelimit by dimensions 200x200 for an album
2. set the resize size to 640x480
2. add an image e.g. 800x800 to that album (dimensions
must be > than the sizelimit and > than the resize size
for that album)
result:
fullsize = 200x150 (or 200x? / ?x200 depending on the
aspect ratio of the originally uploaded items)
resize = 640x480, distorted / upsampled from our new
200x150 original

expected:
fullsize = 200x150
resize: none

solution:
in the SetSizelimitOption, we need to make sure that
the existing derivatives are smaller than the new
originals and if not, remove them.
for thumbnails, maybe keep them if they already were
generated or remove them and generate a new thumbnail
from the original (but don't upsample).