RhodeCode CE/EE

Currently API returns something like this:

{
    "result": {
        "merge_ref": {
            "name": "pr-merge",
            "type": "book",
            "commit_id": "xxxxx"
        },
        "merge_commit_id": "xxxxx", //(same value as the commit_id)
        "executed": false,
        "possible": true,
        "failure_reason": 3
    },
    "id": "mergepr",
    "error": null
}

"failure_reason": 3 is cryptic, we have a translation layer for that already, so we just need tp expose failure_reason_explanation and read it !