Merge pull request #90 from rjc123/mcga

Add rules to support MCGA legacy domain
Update MCGA site rules

The rules added in 767a7eefe80408b0856c9a7ced0daf1a02bdbfea and
599d934da9e615ad13f70a2c1c02b6660e6ea029 are not being used at the
moment because the site is configured as a global redirect appending
path to www.dft.gov.uk/mca. Because the global type case comes before
the Outcome::Status (which would use the rules otherwise) in app.rb
we aren't getting the behaviour we want.

This change adds a pre-emptive rule to replicate a global-path preserving
redirect, with the intent that the path-preserving config will be removed.