Add DuckDuckGo search engine for en-gb locale (both regional and region agnostic version)

Change-Id: Ia837b2085e3fc16b608ee68f558460443a065384
Merge "Add DuckDuckGo search engine for en-gb locale (both regional and region agnostic version)" into cm-10.1
Merge remote-tracking branch 'cm/cm-10.1' into cm-10.1