Initial config for HMRC partial transition

Relevant to www.hmrc.gov.uk/childbenefit and www.hmrc.gov.uk/taxcredits
1. Update corporate mappings to use a timestamp from before the move to gov.uk
2. Update the general timestamp to be more recent, with presumably more coverage
3. Add query string parameters for a tool that may or may not be transitioning as part of this transition phase. [example](http://www.hmrc.gov.uk/tools/taxcredits/results.htm?tickdpmt=28&dates=24%2F12%2F2013)