incremental_statistics: histograms added.
config: histogram parameter "incremental-statistics"->"histogram-bins" added.
json_dump: 25%, 50%, 75%, 90%, 95% quantiles added.
incremental_statistics renamed to statistics.
statistics: tags (min, count, moving_sum, ...) added.
statistics: 'get' and 'get_safe' interface added (min(), sum(), ... is deprecated).
config: 'statistics'->'tags' config option added.
config: interval config sections moved out from public headers.
config: gauge, counter, timer config added (now one can directly configure deltas statistics of counter).
config: use handystats::chrono::clock::duration internally instead of std::chrono::duration (reduces conversion calls).
statistics: tag dependency fixup.
statistics: moving_avg fixup.
statistcs: tag_mask renamed to tags.
config: ability to pass string to "statistics"->"tags" removed (only array of strings is accepted).
config: ability to disable statistics over moving interval and histogram & quantiles (by passing 0 to corresponding parameters) removed.
By now all statistics enable/disable configuration should be done by specifying appropriate tags.
tests: minor fixes.
statistics: histogram's merge heuristic added.
tests: statistics histrogram test added.
statistics: default histogram bins count set to 30.
tests: check new statistics improvements.
config: ability to pass string to "statistics"->"tags" removed (only array of strings is accepted).
use of 'typename' outside of template (even in template specialization) is disallowed.
a class-key must be used when declaring a friend.
internal metrics configured manually (thus, passed user's configuration doesn't affect them).