* Autodetect zzuf in the configure step. It might become handy.

it will eventually evolve into something better.

a file and a memory area into a libcucul buffer.
  * Changed the cucul_import_canvas() prototype so that it uses libcucul
    buffers instead of simple memory areas.

in all .c files that needed it.

cucul_import_canvas().
  * Renamed cucul_create_export() into cucul_export_canvas() for consistency.

their name, eg. cucul_create() -> cucul_create_canvas() etc.
  * Moved buffer-related functions to cucul/buffer.c.

* Renamed canvas handle variables from "c" to "cv". Eh ouais mon gros.

such as cucul_dither_t instead of struct cucul_dither.
  * Made cucul_buffer_t an opaque structure and implemented the two getters
    cucul_get_buffer_data() and cucul_get_buffer_size().
  * Documented all missing functions and function parameters.

parameter to do what both functions did before, and even more.

single frame that was saved by the raw driver.