clean up preprocess.js, add errback
Refactor: promisify styleguide generation steps and move sub-functions outside the main function where possible
Don't fail gulp sass task; notify the UI if there are sass or less errors from preprocessing
Expose only socket compile error and success emits; progress end is emitted in both cases
Merge pull request #193 from jpbackman/refactor-styleguide-main

Refactor: use promises in styleguide.js, use named functions instead of comments, general readability improvements