Update KumaScript to current master
Update KumaScript to current master

- mozilla/kumascript#157 - GroupData: Add Media Session API
- mozilla/kumascript#158 - SpecName, Spec2:  Update HTML5.1, Add HTML5.2
- mozilla/kumascript#159 - Add JSON linter, remove CSS
- mozilla/kumascript#160 - GroupData: Add Cred Mgmt, Intersect Obs APIs

mozilla/kuma,jwhitlock/kuma,jwhitlock/kuma,escattone/kuma,SphinxKnight/kuma,SphinxKnight/kuma,jwhitlock/kuma,Elchi3/kuma,Elchi3/kuma,mozilla/kuma,a2sheppy/kuma,mozilla/kuma,Elchi3/kuma,SphinxKnight/kuma,escattone/kuma,Elchi3/kuma,SphinxKnight/kuma,jwhitlock/kuma,mozilla/kuma,a2sheppy/kuma,a2sheppy/kuma,mozilla/kuma,escattone/kuma,jwhitlock/kuma,SphinxKnight/kuma,Elchi3/kuma,SphinxKnight/kuma,a2sheppy/kuma,a2sheppy/kuma