Bump NBUCore, drops support for iOS 4
Use weak instead of assign
Update copyright
Update Demo
NBUAlertView: Fix selectedIndex bug when there is a cancel button
Fix CocoaLumberjack headers' import
Fix Lockbox headers' import
Use a separate log context for NBUCore
NBULog refactoring

* APP_MODULE_GENERAL -> APP_MODULE_DEFAULT.
* Maximum number of App modules 1 -> 20.
* Separate App log level and module log levels.
* New LOG_LEVEL_DEFAULT.
* Setting App log level resets all modules' log levels.
New NBULogContextDescription
NBUDashboardLogger: Fix iOS 7 bug where the keyboard can't be hidden
NBUDashboard: Add additional fullscreen-only buttons
Support dynamically setting log levels for each context/module from the Dashboard (levels saved to NSUserDefaults)
Update Demo project
NBULogAdjustLevelsTableView: Fix analyzer warnings
Update README version
Specify iOS 5 requirement in Podspec
Update Demo's Pods
Ignore *.xccheckout files
NBULog: Fix weird bug where using NSDictionary subscripts during +load methods would crash on iOS 5