Merge more testing coverage from henrikingo fork

* core_tests.js and navigation_tests.js have more tests
* qunit_test_runner.html runs QUnit in a browser (without karma) and
  provides a generic iframe based platform to test different  presentations.
* copy qunit.js and syn.js into the repo. This allows qunit_test_runner.html
  to work without any dependency on node/npm. (Karma obviously does need them.)
* Move jscs cli option to .jscsrc instead

test/bootstrap.js

@@ -1,12 +1,25 @@
 /*jshint browser:true */
 
-var root = document.createElement( "div" );
-root.innerHTML = [
-  "<div id='impress'>",
-  "  <div class='step' data-x='-1000' data-y='0'>First slide</div>",
-  "  <div class='step' data-x='-800' data-y='0'>Second slide</div>",
-  "  <div class='step' data-x='-600' data-y='0'>Third slide</div>",
-  "  <div class='step' data-x='-400' data-y='0'>Fourth slide</div>",
-  "</div>"
-].join( "" );
-document.body.appendChild( root );
+// TODO: This is the bootstrap file for *karma*. Poorly named (since karma is
+// only one option, in this repo) but keeping the same name now to avoid
+// unnecessary deviation with upstream.
+// If you just want to run the tests locally, you can open test/index.html in Firefox.
+
+// That's annoying: karma-qunit doesn't provide the qunit-fixture element
+// https://github.com/karma-runner/karma-qunit/issues/18
+
+// This file contains so much HTML, that we will just respectfully disagree about js
+/* jshint quotmark:single */
+/* global document */
+
+var fix = document.createElement( 'div' );
+fix.id = 'qunit-fixture';
+fix.innerHTML = [
+'\n',
+'    <iframe id="presentation-iframe"\n',
+'            src="SET THIS IN YOUR QUNIT TESTS"\n',
+'            width="595" height="485"\n',
+'            frameborder="0" marginwidth="0" marginheight="0" scrolling="no"\n',
+'            style="border:1px solid #CCC; max-width: 100%;">\n',
+'    </iframe>'
+].join( '' );