split pySim/legacy/{cards,utils} from pySim/{cards,utils}

There are some functions / classes which are only needed by the legacy
tools pySim-{read,prog}, bypassing our modern per-file transcoder
classes.  Let's move this code to the pySim/legacy sub-directory,
rendering pySim.legacy.* module names.

The long-term goal is to get rid of those and have all code use the
modern pySim/filesystem classes for reading/decoding/encoding/writing
any kind of data on cards.

Change-Id: Ia8cf831929730c48f90679a83d69049475cc5077

setup.py

@@ -3,7 +3,7 @@ from setuptools import setup
 setup(
     name='pySim',
     version='1.0',
-    packages=['pySim', 'pySim.transport', 'pySim.apdu', 'pySim.apdu_source'],
+    packages=['pySim', 'pySim.legacy', 'pySim.transport', 'pySim.apdu', 'pySim.apdu_source'],
     url='https://osmocom.org/projects/pysim/wiki',
     license='GPLv2',
     author_email='simtrace@lists.osmocom.org',