Test for NSFileSystemFreeSize and other file system attributes
Test +[NSJSONSerialization JSONObjectWithData: options: error:] sets error on error
Add tests for +[NSString stringWithContentsOfFile: encoding: error:]
including Android specific system files.
Add basic CFDictionary tests
More NSDecimalNumber tests
Some NSString value tests
Tests of -[NSArray componentsJoinedByString:]
Tests of -[NSObject setValue:forKey:] for different property & ivar types
Minor, remove unintended trace output
Add NSFileManager tests for copying, moving & removing files