Reorder package to src-layout.

Move package to src directory and update project base files for build
process.

MANIFEST.in

@@ -1,4 +1,5 @@
-global-exclude test/*
-global-exclude *.pyc
+recursive-include src/revpimodio *.py
 include LICENSE.txt
+include MANIFEST.in
 include README.md
+include setup.py