[AD] Allegro main function in separate library

[Evert Glebbeek <eglebbk@xxxxxxxxxx>]

This mainly affects OS X.
The attached file contains an "allegro-main" addon that moves Allegro's magic main to an external library, and the necessary changes to the build scripts.
This is necessary in case anyone wants to use bindings to another language from OS X (I don't know about sufficient), or if someone wants to disable Allegro's name mangling. The patch affects the UNIX port in moving umain.c to the addon. This file is normally not used, but there are situations where it might be. The windows port should not be affected.
On any platform, a library "liballegro-main-version.so/dylib/a" is compiled but it may be empty, for instance on Windows or UNIX if no magic main is needed.

Instructions for writing portable code with this addon in place:
 1. use "int main(int, char **)"
 2. link against liballegro-main-version in addition to liballegro-version

Instructions for disabling magic main (when applicable):
 1. #define ALLEGRO_NO_MAGIC_MAIN to avoid any name mangling
 2. don't link against liballegro-main-version
 3. do whatever it is that Allegro requires you to do for it to work in your main function

This completes the last part of removing END_OF_MAIN() from the main library. It is also in my mind the last missing feature between 4.9 and 5.0 as far as the OS X port is concerned (only bug fixing and documenting remain).

Tested on OS X. Someone please confirm that this indeed does nothing in other cases. The iPhone port should probably be changed as well.

Evert

Attachment: allegro_main_addon.tar.gz
Description: GNU Zip compressed data