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/makesdna/DNA_sdna_types.h

@@ -70,7 +70,7 @@ typedef struct BHead4 {
 #
 typedef struct BHead8 {
 	int code, len;
-#ifdef WIN32
+#if defined(WIN32) && !defined(FREE_WINDOWS)
 	/* This is a compiler type! */
 	__int64 old;
 #else

source/blender/makesdna/intern/Makefile

@@ -54,10 +54,14 @@ ifeq ($(OS),windows)
     # _really_ needed, but it is the easiest fix for now. If you have 
     # some spare time, try to trace down the exact dep. Then again, you 
     # could also spend that time making the sdna system more robust.
-    WINLIBS = kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib
-    WINLIBS +=	advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib
-    WINLIBS +=	winmm.lib opengl32.lib glu32.lib largeint.lib
-    WINLIBS +=	/link /nodefaultlib:libc
+	ifneq ($(FREE_WINDOWS),true)
+		WINLIBS = kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib
+		WINLIBS +=	advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib
+		WINLIBS +=	winmm.lib opengl32.lib glu32.lib largeint.lib
+		WINLIBS +=	/link /nodefaultlib:libc
+	else
+		LDFLAGS += -mwindows -mno-cygwin
+	endif
 endif
 
 clean::