This allows users to link against a different CocoaLumberjack than what was provided in YapDatabase previously. Consequently, CocoaLumberjack sources have been removed from the YapDatabase repository.
Moreover, the Xcode-mobile and Xcode-desktop test projects now each have a Podfile. The downside is that you have to run `pod install` before executing the tests the first time around, but the upside is that CocoaLumberjack and YapDatabase libraries are now linked via Pods, and the test projects aren't so dependent on specific versions.
