Listen for SIGUSR1, generate message containing rudimentary report on input channel status for all registered plugins.
Merge branch 'dev' into features/queue-report
Small rearrange, add rudimentary support for plugin-specific data reporting.
Merge branch 'dev' into features/queue-report
Plugin reports are now message.Message objects, and API is exposed for populating a report message from a PluginRunner.
Add router channel data to the report.
Merge branch 'dev' into features/queue-report
use hyphens instead of underscores for heka generated message type names
typo fix
start of report tests.
Slight test code refactor and add test for *PipelineConfig.reports() method.
Need to make sure we whack the Message object before we recycle our holders.
First pass at storing running decoders registry in the PluginRunners, rather than centrally in the PluginConfig. Compiles, not tested.
And that was all it took to get the tests passing again.
Index decoders by UUID instead of integers since integer indexes in a dynamic slice aren't constant, duh.
Merge branch 'dev' into features/queue-report

Conflicts:
	pipeline/config.go
Add some basic tests for the pRunnerBase decoders-related methods.
Major re-org of the decoder life cycle management stuff, now InputRunners are
handed a DecoderSource (underlying type *decoderManager) when they're created,
the decoderManager handles creating and tracking the decoders for that input.
Added `stopped` value to decoderManager structs and reuse stopped decoders
instead of always creating new ones.
Only inputs have decoders now.