generates temp folder

gistfile1.m

- (NSString*) tempFolderPath {
    if(_tempFolderPath == nil) {
        NSError* err;
        _tempFolderPath = [NSTemporaryDirectory() stringByAppendingPathComponent:[[NSProcessInfo processInfo] globallyUniqueString]];
        [[NSFileManager defaultManager] createDirectoryAtPath:_tempFolderPath withIntermediateDirectories:YES attributes:nil error:&err];
        NSLog(@"temporary folder created at %@", _tempFolderPath);
        if(err) {
            NSLog(@"error when creating temporary folder. %@", err);
            // TODO better error handler
        }
    }
    return _tempFolderPath;
}