[3.0] Minify CSS and JS, update dependencies & documentation, fix issues from PR 22

[richard67]

Follow up to PR #22 .

This pull request (PR) for the upcoming new major version 3 adds the minification of CSS and JS to the build process and updates the demo and the documentation for that.

In addition, it fixes following issues which were introduced with PR #22 :

• Multiple share counters were appended to the facebooklike button because the corresponding code was moved inside a loop, and the value and fbValue variables were mixed up.
  See commit 0a94767 for the fix.
• When both services facebooklike and facebook were provided via the data-services attribute in exactly the mentioned order, the facebook button was shown before the facebooklike button, i.e. for these 2 buttons the ordering from the data-services attribute was not respected.
  See commit a118588 for the fix.
• The query selector to get the script src was not adapted to the change script name. Therefore the facebooklike dialog did not get the right link to the stylesheet.
  See commit c96c0cc for the fix.

Finally all dependencies are updated (except of a major update of fontawesome which might be done later).