Change the differ for arrays of strings with newlines in them.

Signed-off-by: Sam Phippen <samphippen@googlemail.com>
Add a changelog entry for the new array differ.

Signed-off-by: Sam Phippen <samphippen@googlemail.com>
Merge pull request #213 from samphippen/differ-newlines

Change the differ for arrays of strings with newlines in them.