##### Summary
fixes#2673fixes#2149fixes#5017fixes#3830fixes#3187fixes#5154
Implements a command API for health which will accept commands via a socket to selectively suppress health checks.
Allows different ports to accept different request types (streaming, dashboard, api, registry, netdata.conf, badges, management)
Removes support for multi-threaded and single-threaded web servers.
##### Component Name
health, daemon
* modularized exporters
* modularized API data queries
* optimized queries
* modularized API data reduction methods
* modularized api queries
* added new directories in makefiles
* added median db query
* moved all RRDR_GROUPING related to query.h
* added stddev query
* operational median and stddev
* working simple exponential smoothing
* too complex to do it right
* fixed ses
* fixed ses
* rewrote query engine
* fix double-exponential-smoothing
* cleanup
* fixed bug identified by @vlvkobal at rrdset_first_slot()
* enable freeipmi on systems with libipmimonitoring; #4440