Describe the "id" parameter of model's sharedCtor

[bajtos]

Extend remoting metadata to describe the "id" parameter accepted
by the sharedCtor of all models.

The description is used by client SDK code generators like loopback-angular.

/to @raymondfeng or @ritch please review.

[bajtos]

Note: it's important to include model name in the description.

AngularJS converts prototype scope methods to static methods, i.e. /products/:id/categories is called by Product.categories({ id: "product-id" }). If the description of the "id" parameter was generic or missing, it would be unclear whether the id parameter is product id or category id.

[slnode]

All is well
Refer to this link for build results: http://ci.strongloop.com/job/loopback/1053/

[raymondfeng]

LGTM