Support for building bf-blender under windows with gcc (huge thanks to

Florian Eggenburger).

Full instructions are in doc/README.windows-gcc.

Main differences from Florian's patch:

- the 'lib' dir should now be the same level as the 'blender' dir (rather
than being a subdir of 'blender'). This is consistent with the other
platforms that bf-blender supports (tuhopuu will also adopt this convention
hopefully soon).

- the script 'free_windows-env.mk' is no longer needed ... see the
docs about how this is overcome (again, tuhopuu will hopefully
also follow this route soon).

- the dlltool dir has it's own Makefile that builds all of the
needed stub libraries from the dll's in cvs.

source/blender/blenloader/intern/readfile.c

@@ -498,7 +498,7 @@ static void switch_endian_bh8(BHead8 *bhead)
 static void bh4_from_bh8(BHead *bhead, BHead8 *bhead8, int do_endian_swap)
 {
 	BHead4 *bhead4 = (BHead4 *) bhead;
-#ifdef WIN32
+#if defined(WIN32) && !defined(FREE_WINDOWS)
 	__int64 old;
 #else
 	long long old;
@@ -1052,7 +1052,7 @@ static void link_glob_list(FileData *fd, ListBase *lb)		/* for glob data */
 
 static void test_pointer_array(FileData *fd, void **mat)
 {
-#ifdef WIN32
+#if defined(WIN32) && !defined(FREE_WINDOWS)
 	__int64 *lpoin, *lmat;
 #else
 	long long *lpoin, *lmat;