Add testing http client
Add http client Request.getHeader(String)
Update CHANGES and NEWS
[maven-release-plugin] prepare release 0.76
[maven-release-plugin] prepare for next development iteration
Remove unused fields
Implement QuantileDigest merging
Add method to dump quantile digest as a graphviz tree
Move thread-safety from QuantileDigest to Distribution
Serialize/deserialize quantile digest
Fix boundary conditions
Only compress if sum(weights) < floor(n/k)

This was inadvertently broken when we implemented exponential decay and make weightedCount a double instead of a long
Don't throw IOException in QuantileDigest serialize/deserialize
Add method to estimate in-memory size of QuantileDigest
Handle the full range of long values in quantile digest
Formatting
Memoize size of QuantileDigest and Node classes to avoid walking their structure every time
Fix bug in quantile digest merge
Fix handling of missing Content-Type for JSON