IE8 Support

[yanatan16]

I have successfully gotten a full pass in IE8 for reactive. To do so, I needed to include #158, make some small adjustments to tests and code, and include a ton of shims. I did this by creating a separate repository: reactive-ie8-shims, which can be included via browserify or prebuilt scripts. Simply shim it in before running any reactive code and you're golden!

[yanatan16]

It should be noted that I ran the full test suite and got a pass:

$ zuul -- test/*
- testing: chrome @ Windows 2008: 29
- testing: firefox @ Windows 2008: 31
- testing: safari @ Mac 10.8: 6
- testing: safari @ Mac 10.9: 7
- testing: iphone @ Mac 10.9: 7.1
- testing: internet explorer @ Windows 2008: 8 9 10
- testing: internet explorer @ Windows 2012 R2: 11
- queuing: <firefox 31 on Windows 2008>
- queuing: <chrome 29 on Windows 2008>
- queuing: <safari 6 on Mac 10.8>
- starting: <chrome 29 on Windows 2008>
- passed: <chrome 29 on Windows 2008>
- starting: <firefox 31 on Windows 2008>
- queuing: <safari 7 on Mac 10.9>
- starting: <safari 6 on Mac 10.8>
- passed: <firefox 31 on Windows 2008>
- queuing: <iphone 7.1 on Mac 10.9>
- starting: <safari 7 on Mac 10.9>
- passed: <safari 6 on Mac 10.8>
- queuing: <internet explorer 8 on Windows 2008>
- starting: <internet explorer 8 on Windows 2008>
- passed: <safari 7 on Mac 10.9>
- queuing: <internet explorer 9 on Windows 2008>
- starting: <internet explorer 9 on Windows 2008>
- passed: <internet explorer 8 on Windows 2008>
- queuing: <internet explorer 10 on Windows 2008>
- starting: <internet explorer 10 on Windows 2008>
- passed: <internet explorer 9 on Windows 2008>
- queuing: <internet explorer 11 on Windows 2012 R2>
- passed: <internet explorer 10 on Windows 2008>
- starting: <iphone 7.1 on Mac 10.9>
- starting: <internet explorer 11 on Windows 2012 R2>
- passed: <iphone 7.1 on Mac 10.9>
- passed: <internet explorer 11 on Windows 2012 R2>
all browsers passed

[defunctzombie]

Yea, automatic travis CI tests never work because of the secure ENV variables in the travis config.

[defunctzombie]

This is brilliant. I will review in more detail tonight and merge.

[yanatan16]

the latest commit updates to a simpler set of shims (version 0.1.2 of reactive-ie8-shims). It removes classList which I mistakenly thought was used, but isn't needed. And it simplifies the eventListener shim a lot. Tests still pass.