Coopr 567: Split server APIs to separate ports.

I have removed ProvisionerHandler from External API and add this handler to Internal API. Also added 
"PUT /v2/plugins/providertypes/{providertype-id}"
"PUT /v2/plugins/automatortypes/{automatortype-id}"
requests to ProvisionerHandler and removed this requests from SuperadminHandler. For now Internal API handles TaskHandler and ProvisionerHandler. I have done some basic tests with coopr standalone - real cluster provisioning via UI.
Could you make the `Names.named()` into constants? Makes it much easier to locate where it's used.