Add models to LDL options

1. Use 'models' to specify the dependencies to other models
2. The 'models' property is an object, such as:

{
    Model1: 'Model1',
    Model2: Model2
}

3. The model classes will be injected into the newly defined class as
static properties using the keys from the models option.
Add a EOL
Merge pull request #55 from strongloop/feature/import-models

Add models to LDL options