Add .mailmap.
Add all contributors to package.json

Contributors have been added alphabetically sorted according to
their first names.
Update node module dependencies.

  * async      : ~0.7.0  -->  ~0.9.0
  * gulp-util  : ~2.2.0  -->  ~3.0.0
  * parents    : ~0.0.2  -->  ~1.0.0
  * through2   : ~0.4.0  -->  ~0.4.2

Module dependencies are now alphabetically ordered (the default
behavior if you add node modules via "npm" command line)
Add homepage and bugs info.
Update documentation.