Fix a crasher and be more robust on corrupt or outdated data-parsoid

* Fixes crasher
http://parsoid.wmflabs.org:8001/result/9d3536b7b58b71c958090a0e99eea3e5467e2907/ar/%D8%AA%D9%8A_%D9%81%D9%8A_%D8%A3%D9%83%D8%B3_%D9%83%D9%8A%D9%88_/_%D8%AF%D8%A8%D8%B3%D9%83
* Deals with absent dp.keys, for example when using cached HTML

Change-Id: I3bed840280e5dda175372684a9447aa1d99d2011
Don't escape '=' in template parameter values

{{echo|1=====}} works just fine. Only the first '=' is consumed. Positional
parameters need to be escaped as before.

Fixes a few parserTests, the blacklist is updated.

Change-Id: I8f3cf9ec2b880b567c57cbe82a35c696c085d217
Merge changes I8f3cf9ec,I3bed8402

* changes:
  Don't escape '=' in template parameter values
  Fix a crasher and be more robust on corrupt or outdated data-parsoid