Reorder package to src-layout, switch to GPLv2 license.

Move package to src directory and update project base files for build
process.
This project change the LICENSE from GPLv3 to GPLv2 after approval of
all contributors:
https://github.com/kjkoster

MANIFEST.in

@@ -1,7 +1,6 @@
-include MANIFEST.in
-include stdeb.cfg
 recursive-include data *
-recursive-include debian *
-recursive-include revpipyload *
-global-exclude test/*
-global-exclude *.pyc
+include LICENSE.txt
+include Makefile
+include MANIFEST.in
+include requirements.txt
+include setup.py