Forces the import scale to 1.

ImportScale.cs

using UnityEditor;
using System.Collections;

public class ImportScale : AssetPostprocessor
{
    public void OnPreprocessModel()
    {
        ModelImporter modelImporter = (ModelImporter)assetImporter;
        modelImporter.globalScale = 1;
    }
}

// Source: http://answers.unity3d.com/questions/12187/import-settings.html
// Must be placed in Editor folder (e.g. "Assets/Editor/ImportScale.cs" or "Anything/Editor/ImportScale.cs")