add a json stats packet type
add logic to domain-server to parse JSON stats
hook JSON stats sending from domain-server
show stats for node at /nodes/UUID
link to node stats page from table
abstract stats packet sending to NodeList
Merge pull request #2459 from birarda/domain-json-stats

add stats handling to domain-server
Merge branch 'master' of https://github.com/highfidelity/hifi