Add StatsToFieldsDecoder.
Add support for generating multiple messages when we have stats with multiple
timestamps.
Merge pull request #442 from mozilla-services/features/stats-to-fields-decoder

Features/stats to fields decoder
Implement `mDRunner`, a wrapper around the dRunner default DecoderWrapper
implementation that a MultiDecoder can hand to any subdecoders that require one.
Add a test for sub-DecoderRunner delegation.
Record change.
Merge pull request #440 from mattcottingham/dev

Fix panic when an invalid config file path is specified
Merge pull request #447 from mozilla-services/features/multidecoder-runner

Features/multidecoder runner
Use a fixed hostname to prevent variability in tests leading to false failures.
Switch to manual statsd message parsing.
Issue #444 Add sandbox configuration options
Merge branch 'dev' into issue_444
Only use `lf` as eol in multiline.log file so tests will work the same way on windows.
Fix case on variable name
Merge pull request #452 from mozilla-services/issue_444

Issue #444 Add sandbox configuration options
Swapped return values.

Applied Rob Miller's remarks about return value order in #44
Updated Changelog regarding #44
Issue #453 Faster double to string conversion
Issue #455 Make the max sandbox process message duration configurable
Fix TcpInput stream parsing.

Each connection requires its own stream parser since they run in parallel.