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

 - [x] Integrity: Added new event 'error[name="config-mismatch"]'
     - Fixes #379

 - [x] Security: Also added filtering to only honor FlashVars. Supersedes #336.
     - Fixes #164
     - Closes #336
     - Still don't have FlexUnit tests in place yet (:sob:), so I'm uncertain if this covers 100% of security holes previously identified in #164 and #336 by @masatokinugawa. However, I've also combined it with a new technique of using `ExternalInterface` to call out and interrogate the DOM for the actual FlashVars (which should help both with security (#164, #336) and in preventing weird browser caching issues for FlashVars (#379)).
     - cc: @jonrohan @masatokinugawa @ptoomey3 @jnewland @mastahyeti &rarr; _Please review!_

 - [x] Also revved version to 2.2.0-beta.3
I was debating just exposing the whole `this.metadata` object here (rather than having a commented out debugging line above). Any opinions on that?  Would that be exposing too much info?