optimize by merging cells

cells on any row of the table then the very first row does not use the
cell-merging optimization; this appears to fix the last of the table
layout bugs seen in truecolor.php; also fix the foreground and
background color bugs seen in truecolor.php.

get hopelessly lost.

are almost there.

split is rendered moot by the plugin system: when enabled, binaries do
not link directly with libX11 or libGL. I hope this is a step towards
more consisteny and clarity.

far better for error checking.

* Use size_t and ssize_t where appropriate.

prototypes. As they are equivalent, this does not break the ABI.

<cucul.h> will provide the C99 types, even if libcaca has been installed.
  * Rename what's left of "common.h" to "stubs.h".
  * Remove all references to erroneous <inttypes.h> from source files.

* Fix the sprite import/export example.

instance.

accordingly.
  * The C++ test example no longer needs "config.h".

cucul_attr_to_argb64() (previously _cucul_attr_to_rgb12bg,
    _cucul_attr_to_rgb12fg and _cucul_attr_to_argb4) in the official
    libcucul API.
  * Cleanup complete: libcaca no longer depends on "cucul_internals.h".

* Updated export test accordingly.

* More debugging information in the import/export and font functions.

the Doxygen documentation.

the now official cucul_attr_to_ansi_[fb]g().

cucul_export_file() but I'm not sure yet this is a good idea.
  * Use the new import/export API in libcaca.

* 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.

the colour.

* Underline support in the X11 driver.

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

as bold or underline. No higher level support for these yet, but at
    least everything is consistent.
  * Created cucul_set_attr_ansi() and cucul_set_attr_argb() which are bound
    to replace cucul_set_color() and cucul_set_truecolor().

output them.

* Fullwidth support in all exporters.

were commas in the canvas.

an explicit cast.

the save/load cursor position trick to ignore them.