BIG change in directory handling:

- Unix users can "make install" and "make uninstall" (as root).
- Installation creates shortcuts "grafx2" and "gfx2cfg" in /usr/local/bin
- Installation puts data files (icon GIFs, gfx2.dat,..) and the actual binaries in /usr/local/share/grafx2
- At runtime, the programs search and create configuration files (gfx2.cfg and gfx2.ini) in ~/.grafx2
(But if there are some present in program's own directory, they override)
- Uninstall removes programs and data, but leaves all users' configurations.

Win32: User's config directory is %APPDATA%\GrafX2
Win98: %APPDATA% is not set by default, so the program falls back to executable's directory.

Tested on Debian Linux
Partially tested on Win XP (early version)
Tested on Win98


git-svn-id: svn://pulkomandy.tk/GrafX2/trunk@365 416bcca6-2ee7-4201-b75f-2eb2f807beb1

io.h

@@ -48,3 +48,10 @@ char * Position_dernier_slash(const char * Chaine);
 #else
   #define SEPARATEUR_CHEMIN "/"
 #endif
+
+//   Détermine si un fichier passé en paramètre existe ou non dans le
+// répertoire courant.
+int Fichier_existe(char * Fichier);
+//   Détermine si un répertoire passé en paramètre existe ou non dans le
+// répertoire courant.
+int  Repertoire_existe(char * Repertoire);