The build was failing with an undefined reference to `_caca_alloc2d`.
This was because the function was internal to libcaca but used by
the `cacaview` utility.

This change makes `_caca_alloc2d` a public function `caca_alloc2d`
by moving its declaration to the public header `caca.h`. All call
sites have been updated to use the new function name.

This fixes the build and allows the Python bindings to be used.

Patch courtesy of Jakub Bogusz.

the future.

speedups when the calling application knows the dirty rectangle covered by
a complex operation.

cases, but that can be fixed.

one dirty rectangle, but this is the first step to improvement.

currently dirty rectangles.

that anything outside the dirty rectangle is guaranteed to be unchanged, but
we currently mark far too many cells as dirty. This must be optimised.

Dirty rectangles are an upcoming optimisation that will tell the output
drivers which portion of the canvas has been really modified since the
last blit.

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.

<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.

without using environment variables..
  * Implement caca_get_display_driver() to return the current display's
    output driver.
  * Add a simple example program to test caca_create_display_with_driver().

create a canvas when so.
  * Add caca_get_canvas() to retrieve the cucul canvas.

drivers no longer need to access the cv->refcount private member
    and __cucul_set_canvas_size() is no longer needed.

functions to access its real data. This is a big API change that will
    break your software, sorry :(

* Do not try to set the terminal title if TERM=linux.

as plugins. This way, libcaca does not directly depend on those libraries.

in all .c files that needed it.

* 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.

remove redundencies in the Doxygen documentation.

that has all the functionality, except it does not work yet (the stdin
    reading routine is missing).

that we have one function less.
  * Fixed coding style.
  * Removed FUCKING TABS.               ____.------.___
                           _______.----'`` ``` `` ``` ``-.
                      _.--' ` ```` ` `  ` ```  ``    ``  ``.
                  _.-'    ' ` `` ```      `` ` `'           `.  _
               .-''      ` H A H A H A `'  M A I S            \/.)
     .    . .-' /       `         `                  `      `` ||
     |`-.(``-.          `      `       `        ' `  `    ```  |\
     `.  '\```\        ``   `     V I E U X   ' ' ``  `-``    -|\\
       `/''````)       `` `          -        -   `````  ' '.' |\_)
        |`'_._`       ```      ''`  P O R C .   . ````        /
        // @) \    `   ``       ''' .              ```      '/
       /''''' |     ` \).`.'-.  ''' _    _         .`` `   '/
     .''''- `-'`.   . //   )--   '/,,',,' ,,,,''__,._`' '  /
   .'    ` `-  `   ' .'   /   ' /,;;;, ,___.---'     \ '' / \
   (`.  .'` __',`''''.--'/   ' /'-----'              | ' /  ))
    `'-'/  `'''_.---' \;;|-  '/            ,,,       | ''|`- |
      `'--'---'        |;|   /   ,,,,;;;;;;;;;;,,,,, |-' /`  |
                       |;|-'|   ,;;;;;;;;;;;;;;;; ;;;/  /|`'''
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                                   ''''