Fixing errors in today extension caused by XCode 6.1

XCode 6.1 introduced this idea of "failable inits" which broke a bunch of things in the today extension.

You can see more details on failable inits here - https://github.com/ksm/SwiftInFlux#failable-initializers-in-objective-c-frameworks.

cc @astralbodies 
Might want to do a nil replace with empty string here since we *might* have a nil NSNumber