BoxOfQuestions specs and MVP implementation

• Construction is now

  var lw = LW.BoxOfQuestions(LW.LWdb('learnWords'));
lw.importFrom(wordlist);

• Library file is generated and may be included with <script src="<path>/LW.js"></script>

• See updated demo.html in public directory

• Added shuffle function for lw.getAnswerOptions()

• SPEC now uses ECMAscript 6 with node 6.9.2

• README updated.

• 27 specs, 0 failures, 1 pending spec