PREPARE rule and did minor cleanup (SCNR).

<bsittler@gmail.com>

* Adapt the swallow test to the display's size.

* Swallow 4 applications instead of 2 in the swallow test.

properly export cucul_utf8_to_utf32(). Evil API breakage, but no one
    uses these functions anyway.

to cucul_import_memory() and try again later if it says "not enough data".

* Updated the caca importer to reflect that; only one frame is read at the
    moment.
  * Added an "utf8cr" export format for UTF-8 + CRLF exports.
  * Updated cacaserver to reflect file format changes.

cucul_set_color() and cucul_set_truecolor() under the new names
    cucul_set_color_ansi() and cucul_set_color_argb().
  * Renamed cucul_get_color_name() into cucul_ansi_to_str().

functionality into cucul_set_attr().
  * Add cucul_ansi_to_attr() and cucul_argb_to_attr().
  * Rename CUCUL_COLOR_* to CUCUL_*.

with cucul_set_attr_ansi(). Old application will still compile (but issue
    a warning) and run, though.

few seconds at the beginning.