Use LESS clean CSS plugin

static/css/less.install

@@ -4,6 +4,7 @@
 if [ ! -e "$(which lessc)" ] ; then
     if [ ! -e "node_modules/.bin/lessc" ] ; then
         npm install less
+        npm install less-plugin-clean-css
     fi
 else
     echo LESS $(npm view less version 2>&1 | grep -v WARN) is installed

static/css/makefile

@@ -6,7 +6,7 @@ endif
 export LESSC
 
 all :
-	$(LESSC) -x app.less house.css
+	$(LESSC) app.less --clean-css="--s1 --advanced --compatibility=ie8" house.css
 
 local : all