privoxy: moved to github and update to 3.0.22

- moved from oldpackages to github
- set maintainer
- update pkg source to new version 3.0.22
- run privoxy as non root user privoxy:privoxy
- using procd including network events to restart on changes
- log start and stop to syslog, privoxy not using syslog

Signed-off-by: Christian Schoenebeck <christian.schoenebeck@gmail.com>