Redo window mkdir; add cross-platform rmdir

tools/export/gcc_arm_common.tmpl

@@ -1,10 +1,13 @@
 # This file was automagically generated by mbed.org. For more information, 
 # see http://mbed.org/handbook/Exporting-to-GCC-ARM-Embedded
 
+# cross-platform directory manipulation
 ifeq ($(OS),Windows_NT)
-	MAKEDIR = IF exists $(1) () ELSE (mkdir $(1))
+    MAKEDIR = if not exist "$(1)" mkdir "$(1)"
+    RM = rmdir /S /Q  
 else
-	MAKEDIR = [ -d $(1) ] || mkdir -p $(1)
+    MAKEDIR = mkdir -p $(1)
+    RM = rm -rf 
 endif
 
 ifeq (,$(filter bin,$(notdir $(CURDIR))))
@@ -19,7 +22,7 @@ $(OBJDIR):
 Makefile : ;
 % :: $(OBJDIR) ; :
 clean :
-	rm -rf $(OBJDIR)
+	$(RM) $(OBJDIR)
 {% block target_clean -%}
 {% endblock %}
 else