Fix unit tests line endings issues
Allow embedding CSS and JavaScript files into HTML

- usage (CSS example):
1) includes all styles inside build block

  <!-- build:css inline -->
  <link rel="stylesheet" href="styles.css">
  <link rel="stylesheet" href="styles.css">
  <!-- /build -->

2) replace styles inside build block and inline CSS from styles.css

  <!-- build:css:dist inline styles.css -->
  <link rel="stylesheet" href="styles1.css">
  <link rel="stylesheet" href="styles2.css">
  <!-- /build -->