Enable aggregation, curl_json, fhcount, log_logstash, memcached,
threshold, write_log & write_riemann plugins.
Add dependencies on devel/libyajl for curl_json & log_logstash and
devel/protobuf-c for write_riemann.
Add a README explaining how to run the daemon as _collectd user in case
you dont need the dns and ping plugins (the only ones requiring root).
Lots of patches merged upstream.
From Pavel Korovin with small tweaks by me, tested here on ppc.
2b05235748