raster.c: need ceilf(large_bar_height * si) to avoid zero height rows;

also improve non-half-int interpolation performance
raster/vector.c: use new stripf() func in "common.c" to workaround gcc
  32-bit float calculation variations
gs1.c: allow dummy AI "[]" if GS1NOCHECK_MODE and has data (#204);
  also add note re TPX AI 235 and terminating FNC1
Remove trailing whitespace in various files

backend/Makefile.mingw

@@ -52,7 +52,7 @@ all: $(DLL) $(STATLIB)
 %.o:%.c
 	@echo Compiling $< ...
 	$(CC) $(CFLAGS) $(DEFINES) $(ZINT_VERSION) -c -o $@ $<
-	 
+
 $(DLL):$(DLL_OBJ)
 	@echo Linking $@...
 	o2dll.sh -o $@ $(DLL_OBJ) $(LIBS)