Output uglificationMap too

[TheJaredWilcurt]

To perform some logic (like removing duplicate markup classes) other tools will need a reference for what the class names represent.

{
  atomizedCss: '.rp_0 { padding: 8px }',
  classMap: {
    'active': ['rp_0']
  },
  uglificationMap: {
    'rp__0': {
      index: 0,
      usedBy: [
        'active'
      ],
      normal: 'rp__padding__--COLON8px',
      property: 'padding',
      value: '8px'
    },
    // Even if using uglify: false we would still want this, like so:
    'rp__padding__--COLON8px': {
      index: 1,
      usedBy: [
        'active'
      ],
      normal: 'rp__padding__--COLON8px',
      property: 'padding',
      value: '8px'
    }
  }
}

Users could derive specificity by checking the index of each class:

Object.keys(uglificationMap).indexOf('rp__0');

However, this should just be baked in, as a index key to make logic simpler.
When generating these from semantic classes, we can push that semantic class onto the usedBy array. I don't see a use case for this at the moment, however this information may be useful for other tools, and likely won't be difficult to provide.