Add a missing keyword on refresh mock

ShellApp.refresh can also receive a rollback. Although we ignore it here, if
some stoq gui tests break this will generate a lot of tracebacks. Have no idea
why this doesn't break when there's no errors on the tests.

Change-Id: Ibdfaab161f38e91d6d00bacdbaf03bb2e9fd22d8
Grab focus on applications by default too

Change-Id: I4ed70436fcd0a705ac732d53996829c0705f475a