Fix an error with the LESS process which was breaking make

Use an older version of LESS

Makefile

@@ -55,7 +55,7 @@ $(CSS_OBJ): www/less/map.less $(LESSC) $(LESSHAT) $(WDN_MIXINS)
 	$(LESSC) --clean-css $< $@
 	
 $(LESSC):
-	npm install less
+	npm install less@1.7.5
 
 $(LESS_LIB)/%.less:
 	@mkdir -p $(@D)