robbiehanson/CocoaLumberjack — pull request #127 by kevinkirkup (2013-07-14 22:44:17+00:00)
Title: Xcode 5 Static Analyzer: NSDictionary can not contain nil objects

The static analyzer in Xcode 5 complains that NSDictionary can't contain
nil objects.

Set a default empty NSString if any nil objects are found
in the DDFileLogger.