The target of the right log entry is shown with namespace prefix, but it
is always a user, so skip the namespace prefix.
Change-Id: Ibe6005cc70ff3933836166d97c544267fb7d9951
Test the LogFormatter by passing old and new database rows to it.
The text shown on Special:Log and the api result returned by
list=logevents is tested.
Change-Id: Icfcba506f4fa3010cdaf973aa2df23b6e92c25e4