privoxy: moved to github and update to 3.0.22 (revised)

* 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>