* rendering: headless chrome progress
* renderer: minor change
* grpc: version hell
* updated grpc libs
* wip: minor progess
* rendering: new image rendering plugin is starting to work
* feat: now phantomjs works as well and updated alerting to use new rendering service
* refactor: renamed renderer package and service to rendering to make renderer name less confusing (rendering is internal service that handles the renderer plugin now)
* rendering: now render key is passed and render auth is working in plugin mode
* removed unneeded lines from gitignore
* rendering: now plugin mode supports waiting for all panels to complete rendering
* fix: LastSeenAt fix for render calls, was not set which causes a lot of updates to Last Seen at during rendering, this should fix sqlite db locked issues in seen in previous releases
* change: changed render tz url parameter to use proper timezone name as chrome does not handle UTC offset TZ values
* fix: another update to tz param generation
* renderer: added http mode to renderer service, new ini setting [rendering] server_url
* fix(alerting): fixed evaluation for no_value condition, fixes#7244
* feat(alerting): moving null library into grafana, fixing handling on no value / no series
