High-level problem:
cserve2 does not support load_opts properly when opening an image.
As a result, when (pre)loading a JPEG file with specific load
options (eg. w, h, region and orientation), the image buffer might
have the wrong dimensions.
So, we need to use load_opts when computing file hash key.
And, pass these load options to the loader slave,
and use them while OPENING the image. This will set
properly the geometry.
Fixes test "Preload and Prescale" in elementary_test.
Pass around "animated" flag for images that can be animated.
Fallback to local cache if the image is animated.
Implementing support for animated images in cserve2 does
not seem to make a lot of sense considering each frame must
be requested independently in real time,... and to be honest
there doesn't seem to be any valid use case anyway :)
Shared string indexes are not repacked, since they live in a
memory pool (where the indexes can be reused).
So, the index in the table is equal to their ID. Add initial
test to check if the item at index n has the ID n.
Jean-Philippe Andre