Support for default resolution added.
Default resolution is determined by CCFileUtil's searchResolutionsOrder array and is mapped to a sprite builder resolution.
CCPackageManager now offers a simple method to download a package only by providing a name.
CCPackage can now be initialized with a name only.
Some tests added for these cases, although CCPackageHelper tests are disabled at the moment due to a bug in CCFileUtils and handling of searchResolutionsOrder.
Packages loading and saving moved to CCAppDelegate.