Introduce a Python module structure

This is a simple move of Python code that wraps common QEMU
functionality, and are used by a number of different tests
and scripts.

By treating that code as a real Python module, we can more easily:
 * reuse code
 * have a proper place for the module's own unittests
 * apply a more consistent style
 * generate documentation

Signed-off-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Caio Carrara <ccarrara@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20190206162901.19082-2-crosa@redhat.com>
Signed-off-by: Cleber Rosa <crosa@redhat.com>
diff --git a/scripts/device-crash-test b/scripts/device-crash-test
index 2a13fa4..a674891 100755
--- a/scripts/device-crash-test
+++ b/scripts/device-crash-test
@@ -25,6 +25,7 @@
 """
 from __future__ import print_function
 
+import os
 import sys
 import glob
 import logging
@@ -34,6 +35,7 @@
 import argparse
 from itertools import chain
 
+sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'python'))
 from qemu import QEMUMachine
 
 logger = logging.getLogger('device-crash-test')