Response from REST when there's an error is still 200

[dotasek]

Relevant to the feature/cyrest branch

To replicate, load galFiltered.cys and click some blank space in the Network Control Panel to make the current network null.

Execute POST /mcode/v1/analyze with the default arguments.

The object returned contains only a partial CIError object, and also returns a 200 code instead of an HTTP error code such as 404 (for missing resource, which a null network would be).

A similar output from the Diffusion returns response code 404 and contains this object:

{
  "data": {},
  "errors": [
    {
      "status": 404,
      "type": "urn:cytoscape:ci:diffusion-app:v1:diffuse_current_view:1",
      "message": "Could not find current Network",
      "link": "file:/Users/hodor/CytoscapeConfiguration/3/framework-cytoscape.log"
    }
  ]
}