automate release process a bit more

[tvo]

Now it consists of:

• update CHANGES.txt (new version number, date, description)
• update setup.py (new version number)
• create tag (git tag -a vX.Y.Z -m 'version X.Y.Z')
• git push origin master --tags
• python setup.py sdist upload

Entering version number and description once should be sufficient for a release. Maybe make release?

[tvo]

release script

Closed by 4c65215393faac28a41517badee104f2e8318086