Integrity: Added new event 'error[name="version-mismatch"]'

Fixes #254

Especially for you & the :octocat: crew, @jonrohan. :gift_heart:

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Added JS unit tests, and also tested manually by using a new SWF with an old version number.

From the manual test:

 1. Before hooking up ZC clients:

     ![image](https://cloud.githubusercontent.com/assets/417751/5144837/4d1446f2-7163-11e4-8e18-4ded124ff292.png)

 1. When the SWF loads:

     ![image](https://cloud.githubusercontent.com/assets/417751/5144882/c589837c-7163-11e4-86c9-8db51b090379.png)