OS X Launcher needs to support the new ContentFilter errors

[nleme]

Recently, I modified the Readium SDK and the iOS and Android Launchers to support ContentFilter errors. Basically, I created a new architecture so that the ContentFilters can report that they had an error when trying to filter bytes from a given resource.

In the iOS and Android Launchers, that error will bubble all the way up to the app, so that the app can display or log something about the given error. The idea is that people using the Readium SDK in their iOS and Android apps can copy the code to deal with their own ContentFilter errors.

However, I have not done so for the OS X Launcher. Presently, I do not have the time to do that, so it would be up to somebody who has the time to modify the OS X Launcher so that it will receive ContentFilter errors and potentially do something with them (like displaying a message or writing a log).

It should not be a difficult task, basically the person doing this would just have to do something very similar to what I did for iOS.