IE8 support

Hello.

I am working on a project that needs to support IE8+ and decided to use virtual-dom. I made this decision after reading comments on the issue #91 and a few other remarks that this project wants to stay compatible with older browsers.

I have gotten quite far with my implementation and IE8 actually works, to a point. I hit a bug this evening – an IE8 quirk that virtual-dom does not work around. I wanted to create a PR but after trying to run the test suite it seems nobody actually tests on IE8. For example, IE8 complains about "class" being a reserved name when used as an object property.

These are small things, easy to fix. However, the test suite still does not run on IE8. After 4-5 "unresponsive script" popups it consistently errors out on tests-bundle.js:2515 (something inside the process.nextTick implementation):

    return function nextTick(fn) {
        setTimeout(fn, 0);
    };

I really do not know what this means but the whole test suite fails on IE8 (at least my experience). Could you please advise how I could submit a PR to fix an IE8 bug without a working test suite? With all the time invested so far I really need to fix that bug.

Thank you!