Patch collection from Volker Grabsch to help Tux Paint cross-compile for Windows:

* Solve the 'FIXME: "finddir" ...' (The trick is to use "=" instead of ":=". That way, $(beos_PREFIX) will only be evaluated when it is actually used.)
* include "shlwapi.h" instead of "Shlwapi.h" (Otherwise, compiling for Windows will fail on a case sensitive file system. (e.g. a Unix file system when cross compiling))
* use FILENAME_MAX instead of NAME_MAX (FILENAME_MAX is more portable than NAME_MAX. Also, recent MinGW versions don't support NAME_MAX anymore.)
* Exposing font_thread_aborted via extern [tweak to Volker's patch which removed a logic test, which is probably not what we want]
* include parse.h (and thus compiler.h) after <stdio.h> (This ensures that the perror() macro of compiler.h won't confuse the perror() function declaration of <stdio.h>.)
* fix another compiling error about undefined variables (The tuxpaint.c uses printcommand/altprintcommand/papersize even when they aren't defined, i.e. when libpaper is not used. This patch solves the issue by using "#ifdef PAPER_H")
* call show_available_papersizes() only when libpaper is used
* permit cross compiling by using Make variables instead of hard-coded tools

Documented scottmc's Haiku improvements.

src/parse.gperf

@@ -6,13 +6,13 @@
 
 %{
 
-#include "../src/parse.h"
 #include <string.h>
 #include <stddef.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <ctype.h>
 #include <stdint.h>
+#include "../src/parse.h"
 
 const char PARSE_YES[] = "yes";
 const char PARSE_NO[]  = "no";