[PostCSS] plugin added cachebuster to local files based on their datechanged.

@import url("/css/styles.css");
.foo {
  background-image : url('../images/index/logo.png');
  behavior : url('../behaviors/backgroundsize.min.htc');
}
@font-face {
  font-family: 'My font';
  src: url('fonts/myfont.ttf');
}

@import url("/css/styles.css?v66f22a33fff");
.foo {
  background-image : url('../images/index/logo.png?v14f32a475b8')
  behavior : url('../behaviors/backgroundsize.min.htc?v15f55a666c2');
}
@font-face {
  font-family: 'My font';
  src: url('fonts/myfont.ttf?v32f14a88dcf');
}

postcss([ 
  require('postcss-cachebuster')({
    imagesPath : '/images', 
    cssPath : '/stylesheets'
  }) 
])

See [PostCSS] docs for examples for your environment.

• cssPath - option to redefine relative images resolving directory (by default the same as css file folder)
• imagesPath - variable to define absolute images base path
• type - define cachebuster type, mtime by default, allows: mtime, checksum (checksum based on a hash algorithm), or a function which receives the absolute path to the file as an argument and whose return value becomes the url pathname.
• paramName - prefix for the cachebuster value added to an asset's query string (defaults to v). The default of v produces URLs like images/horse.jpg?v32f14a88dcf. You can include an = to format it as a key/value parameter. For example, setting paramName to v= could produce URLs like images/horse.jpg?v=32f14a88dcf.
• hashAlgorithm - the hash algorithm to use when type is set to checksum (defaults to md5). See the crypto.createHash() documentation for information about available hash algorithms.
• additionalProps - array of additional CSS properties to support
• supportedProps - replacement array of supported CSS properties (see below for the default list of supported properties).

Default supported properties:

• background
• background-image
• border-image
• behavior
• src

Add to this list by setting the additionalProps configuration option. To add support for mask-image properties, for example:

postcss([ 
  require('postcss-cachebuster')({
    additionalProps : [
      'mask-image',
      '-webkit-mask-image'
    ]
  })
])

Replace the default list by setting the supportedProps configuration option. To limit the cachbusting to background images only, for example:

postcss([ 
  require('postcss-cachebuster')({
    supportedProps : [
      'background',
      'background-image'
    ]
  })
])

• Gleb Mikheev (https://github.com/glebmachine)
• Graham Bates (https://github.com/grahambates)
• Yusuke Yagyu (https://github.com/gyugyu)
• Jackson Ray Hamilton (https://github.com/jacksonrayhamilton)