Convert pvc-client-cli into a proper Python module

Also fixes up the Debian packaging such that this works how I would
want, with proper module installation while leaving everything else
untouched. Finally implements automatic installation and removal of the
BASH completion for the PVC command.

client-cli/setup.py

@@ -0,0 +1,20 @@
+from setuptools import setup
+
+setup(
+    name='pvc',
+    version='0.9.20',
+    packages=['pvc', 'pvc.cli_lib'],
+    install_requires=[
+        'Click',
+        'PyYAML',
+        'lxml',
+        'colorama',
+        'requests',
+        'requests-toolbelt'
+    ],
+    entry_points={
+        'console_scripts': [
+            'pvc = pvc.pvc:cli',
+        ],
+    },
+)