Log Message:
gegl: update to 0.4.2.

GEGL-0.4.2 2018-05-15

Build

Abort early if autoreconf fails, remove unused bits, default to -Ofast
as CFLAGS.

GeglBuffer

Improve concurrency for trimming and destruction of tile caches.
Improve cache invalidation during partial mipmap regeneration.

Do new cheap clones of buffers with new internal gegl-buffer backed
tile-backend.

Do not keep cached sampler in buffer it makes cache invalidation hard,
and for performance/threading it is better to create ones own samplers
anyways. The old API still exists, though parts of it is now
deprecated. The single special case where gegl_buffer_sample remains
somewhat performant is with the NEAREST sampler, for all other samplers
creating a caching sampler is better.

Operations

operation: add GeglOperationAreaFilter::get_abyss_policy() vfunc
Copyright notice improvements to spherize, color-overlay. ff-save:
implement defines handling compilation with ffmpeg 2.3-2.7, 4.0 compat.

Improved multi-threaded performance of panorama-projection and other
transformation operations through optimizations in buffer and
base-classes.

Contributors

code improvements and translations from: Daniel Korostil, Debarshi Ray,
Dimitris Spingos (Δημήτρης Σπίγγος), Ell, Franz Brausse, Jehan, Jordi
Mas, Marco Ciampa, Øyvind Kolås, and Sebastian Pipping.