GitLab

No more hardcoding :)

fix a typo and a memory leak

The original scale-size requires to pass both height and width.
scale-size-keepaspect will calculate one from the other, preserving
the original aspect ratio if only one is specified.
If no dimensions are specified, keeps original dimensions.

Peeks inside at the content-type to determine loader to use.
Tested for png and jpg files.

Relies on the extension just like file paths. Not ideal, but
tricky to do much better without fetching URI and checking
content-type (could be done for HTTP for instance).

Remove linear buffers and use GeglSampler for input buffer and GeglIterator for output buffer.