Errors produced by unzipping task are written to stderr now instead of read by SB.
Error data was never used.
Syncing with MainThread now working if by any coincidence updater is already running on MainThread.
Refactoring: Making use of convenience category for NSAlerts.
URL opened upon succes moved to a constant.
Refactoring: Moved SemanticVersioning class to Cocos2dUpdater group.
Converted ivars to properties.
Merge pull request #784 from NickyWeber/bugfix/#782_cocos2dupdater_freeze

Bugfix/#782 cocos2dupdater freeze