Don't fuse strings around and between packed rules

Just leave everything to PostCSS. This could fix #17. This fixed test
also resolve #18.

README.md

@@ -170,7 +170,6 @@ Becomes:
   .foo {
     width: 100px;
   }
-
   .baz {
     width: 300px;
   }

lib/css-mqpacker.js

@@ -2,23 +2,6 @@
 
 var postcss = require('postcss');
 
-var _fuseStrings = function (a, b) {
-  var i = 0;
-  var s = '';
-  var j = 0;
-
-  for (i = b.length; i > 0; i--) {
-    s = b.substring(0, i);
-    j = a.lastIndexOf(s);
-
-    if (j >= 0 && j + s.length === a.length) {
-      break;
-    }
-  }
-
-  return a + b.substring(i);
-};
-
 var _process = function (css) {
   var queries = {};
   var params = [];
@@ -32,11 +15,9 @@ var _process = function (css) {
     var past = queries[query];
 
     if (typeof past === 'object') {
-      rule.first.before = _fuseStrings(_fuseStrings(past.after, rule.before), rule.first.before);
       rule.each(function (r) {
         past.append(r);
       });
-      past.after = rule.after;
     } else {
       queries[query] = rule;
       params.push(query);

test/expected/between-the-packed-rules.css

@@ -1,12 +1,11 @@
+
 @media (min-width: 999px) {
   .foo {
     z-index: 1;
   }
-
   .bar {
     z-index: 2;
   }
-
   .baz {
     z-index: 3;
   }

test/expected/multi.css

@@ -1,30 +1,24 @@
 @charset "UTF-8";
-
 @media (min-width: 99px) {
   .foo {
     z-index: 1;
   }
-
   .bar {
     z-index: 2;
   }
 }
-
 @media (min-width: 999px) {
   .baz {
     z-index: 3;
   }
-
   .qux {
     z-index: 4;
   }
 }
-
 @media screen and (min-width: 999px) {
   .quux {
     z-index: 5;
   }
-
   .corge {
     z-index: 6;
   }

test/expected/query-order.css

@@ -1,15 +1,12 @@
 @charset "UTF-8";
-
 @media (min-width: 99px) {
   .foo {
     z-index: 1;
   }
-
   .bar {
     z-index: 2;
   }
 }
-
 @media (min-width: 999px) {
   .foo {
     z-index: 3;

test/expected/simple.css

@@ -26,11 +26,9 @@
   .foo {
     z-index: 4;
   }
-
   .bar {
     z-index: 5;
   }
-
   .baz {
     z-index: 6;
   }