use classList to toggle css classes if it exists

Default css binding does not work for svg, the problem is attribute className, so these changes must fix the issue.
forgot else condition
add some tests
use classList to toggle css classes if it exists
use classList to toggle css classes if it exists
Prefer classList over className

Closes #1594 ; see also #337

Refactored the CSS toggle tests so that they are run for both className and classList scenarios.
Revert the tests for CSS/classList

Also, add test when the browser supports SVG
SVG/classList test pass for IE10+; skip for <= IE9
Merge remote-tracking branch 'upstream/master' into fix-svg-css-binding

Conflicts:
	spec/defaultBindings/cssBehaviors.js
Fix conflict in cssBehaviors
always run the css/SVG test
Fix trailing spaces
Fix classList add/remove accepting one class only
Fix svg w/o classList test for some browsers
Fix for browsers with no classList on svg

Some browsers have both svg and classList support but no classList support on svg tags.

To support those cases one would have to use `setAttribute` and `getAttribute`, which (conferring no benefit to the usual case with a more modern browser) might better be done in a custom binding e.g. `svgCss`.
Remove whitespace
Fix for cases where SVG does not have classList

This fixes for namely IE and some WebKit (Safari, Android).

Tested on: Firefox, Chrome, Safari, PhantomJS
Access className property with ['baseVal']
Update comments re. changing node classes
Simplify SVG test; update comment.