rapidjson: correctly handle NaN values, small double values
srw: removed dumping @info result to the log
monitor: using handystats library to gather runtime statistics

 - instrumented process_raw and cache
 - compile time option WITH_STATS allows to enable/disable handystats
   instrumentation at compile time (WITH_STATS is ON by default)
 - integration into monitor service with new category "stats"
   (native, http, python binding)
 - config: "handystats_config" option bears the name of handystats config
   file, could be omitted, handystats will run on defaults then
monitor: complete replacement of react
monitor: added support for formatted metrics names
monitor: update to handystats 1.9.8
monitor: io input/output/commands stats fixed and improved
example: added sample config file for handystats
example: monitoring-stats.txt lists measured values
monitor: update to handystats 1.10
Merge pull request #509 from ijon/handystats

Instrumentation with handystats and replacement of react