Merge pull request #146 from hashicorp/fix-prometheus-panic

prometheus: prevent panic when incrmenting counter

Add placeholder constant for JS (#158)

This is necessary for users of this library who might be building
with the WASM target.

Merge pull request #155 from hashicorp/biazmoreira/addgaugefloat64-sink

Add PrecisionGauge to Circonus

Prevent dogstatsd sink from clobbering the metric key for other sinks (…

…#156)

If using the Fanout sink and including the dogstatsd sink, any sinks sent the metric AFTER dogstatsd could see invalid metric names. This was due to some inadvertent modifications to the original metric key. The new implementation ensure that when modifying the orignial metric key, a new backing array is used and will have key parts copied into it instead of changing elements in the original metric key.

Merge pull request #138 from jrasell/jrasell/f-improve-prom-flatten-k…

…ey-perf

prometheus: improve flatten key performance.

Merge pull request #135 from armon/shutdown-refactor

Refactor Shutdown into a separate interface to revert breaking change.

Merge pull request #132 from ggambetti/ggambetti/metrics-shutdown

Adds Shutdown to Metrics API

Merge pull request #129 from FFMMM/describe-descriptors

actually describe PrometheusSink descriptors

Merge pull request #125 from dnephin/dnephin/stream-metrics

inmem: allow streaming of metrics as intervals complete

Merge pull request #124 from dnephin/dnephin/fix-inmem-mutex-copy

InmemSink: create a new RWMutex , because they are not safe to copy