- new builtin datasource plugin "Logging" (likely going to be renamed)
- plugin implements no panel ctrls yet, only ships datasource
- new models for logging data as first class citizen (aside from table
and time_series model)
- Logs as new view for Explore
- JSON view for development
Testable only against existing logish deployment.
Then test with queries like `{job="..."} regexp`.
* devenv: working on dev env setup & dashboards
* devenv: refactored testdata app to a built in datasource instead, and moved dashboards to a devenv provisioned dashboards
