makefiles: Added a rule for building BMPs from SVGs.

Make.rules.in

diff --git a/Make.rules.in b/Make.rules.in
index 7b571ed..cc6d602 100644
--- a/Make.rules.in
+++ b/Make.rules.in
@@ -136,7 +136,7 @@
 
 # Implicit rules
 
-.SUFFIXES: .mc .rc .mc.rc .res .idl .tlb .h .y .l .tab.c .tab.h .yy.c .ok .man.in .man _c.c _i.c _p.c _s.c .cross.o @MAINTAINER_MODE@ .sfd .ttf .svg .ico
+.SUFFIXES: .mc .rc .mc.rc .res .idl .tlb .h .y .l .tab.c .tab.h .yy.c .ok .man.in .man _c.c _i.c _p.c _s.c .cross.o @MAINTAINER_MODE@ .sfd .ttf .svg .ico .bmp
 
 .c.o:
 	$(CC) -c $(ALLCFLAGS) -o $@ $<
@@ -192,6 +192,11 @@
 .svg.ico:
 	CONVERT="$(CONVERT)" ICOTOOL="$(ICOTOOL)" RSVG="$(RSVG)" $(BUILDICON) $< $@
 
+.svg.bmp:
+	$(RSVG) $< $<.png
+	$(CONVERT) $<.png -alpha off $@
+	$(RM) $<.png
+
 # Rules for IDL files
 
 dlldata.c: $(WIDL) Makefile.in