* Helps reduce garbage (MakeMetric() now takes a slice and there's a shorter version MakeSingletonMetric())
* Fixes bug computing Max (Min) in samples since using MakeMetric()
was causing a default Max/Min of zero.
* Simplifies code a bit
Also:
* Remove Gob encoder/decoder
* Stop using custom encoders/decoders for Timestamps (both ugorji and the Golang JSON codecs use nanosecond precision).
* Use idiomatic way to check for existence in metric.LastSample()
* New encoding format:
* Msgpack reports between probe<->app (smaller representation, faster to
encode/decode).
* Still use JSON between app<->UI (try to avoid making javascript deal with
mspack).
The app still suports publishing reports in both gob and JSON, not braking
backwards compatibility.
* Use compile-time generated marshallers/unmarshallers for higher performance. In
order to be able to skip code-generation for certain types, I included
https://github.com/2opremio/go-1/tree/master/codec/codecgen instead of
upstream until https://github.com/ugorji/go/pull/139 is merged.
* Encode/decode intermediate types using github.com/ugorji/go/codec.Selfer
for higher performance and reducing garbage collection (no temporary buffers).
- base load graph x-axis on data, not a hardcoded window
- format memory dynamically to scale
- add some tests for the immutability of metrics
- use ps.List for Sample storage, so it is immutable. Have to implement custom marshalling
- adding tests for report.Metrics
- check the ordering of the json samples
- Make the nil value for Metrics valid.
- Sort samples from oldest to newest on the wire.
