1. relative references ".csar import" fail in all .py

2. error on yaml loading file (csar_parser.py)
svc_template = yaml.load(file(filename, 'r'), Loader=yaml.UnsafeLoader)
to avoid error message on Loader

3. preload.py not detecting strings since they now are unicode
elif type(v) is str or type(v) is str or type(v) is unicode: