Added support for collectd messages. Added support for more than one value in VALUES collectd part. Fixed graphite broker to nicely deal with multiple values. Fixed graphite graphs to support multiple values by showing '.*' of that metric.
Added proper support for counter/derive/absolute datatypes, by taking the derivative. Removed debug logging.
Added collectd_disk.trig example
Added collectd header in shinken-specific.cfg
Merge pull request #802 from anonimoose/master

Added support for messages, multiple values and derivative approach to derive/absolute/counter types.