rewrite catch use, prettify collectd reporter
exometer_report fixes
Introduce statds reporter.

In addition to supporting a very basic stock-statsd integration, this reporter
includes a DataDog dogstatsd type: set. No other non-standard features are
supported. Configuration items are hostname, port and type_map.

Signed-off-by: Brian L. Troutwine <brian.troutwine@adroll.com>