mitigates https://github.com/ebiwd/EBI-Framework/pull/96

Replace polyfill for window.ga (the Google Analytics callback) with a if-exists-call

Google tells you to use analytics by including this snippet:
<script>
  (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
      (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
    m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
  })(window,document,'script','https://www.google-analytics.com/analytics.js','ga');

  ga('create','unique tracker id', 'auto');
  ga('send', 'pageview');
</script>

i[r] is window['ga'] and if it's something truthy ([] is truthy) the snippet does nothing.

At the same time foundationExtendEBI.js can not rely on window.ga being there (individual teams will have their own tracker, or not) so add an if-exists-then before each function call.

This seems to have been removed when foundation went to  6.3, and
wasn’t added back.

For:  #84

Needed as we’re going stable and 6.4 is a big change.

This continues efforts to be more Angular/react/ect/JS friendly.
invokeResponsiveMenuEBI and activateEMBLdropdown can now be re-inited.

See #92

For #90

Workaround for regression introduced in 1.6.1: https://github.com/maxogden/extract-zip/issues/43

#88