- update README.md, add features and dependencies
- update comment in after-install.sh script

ignore wheelhouse and *.deb

- bugfix: add "set -e" in utils/build-deb
- separate dev and prod requirements.txt files.
  do not install dev packages in prod. do not package them in deb.
- full-clean now also clean wheelhouse/
- update default pylint to 1.2.0

- use wheel to support "make deb"
- use private index at apt.yygamedev.com to fetch yygame-utils