Fix default setting (#740)

* push validate/defaults into datastore

we weren't setting a timestamp in route insert when we needed to create an app
there. that whole thing isn't atomic, but this fixes the timestamp issue.

closes #738

seems like we should do similar with the FireBeforeX stuff too.

* fix tests

* app name validation was buggy, an upper cased letter failed. now it doesn't.
uses unicode now.
* removes duplicate errors for datastore and models validation that were used
interchangably but weren't.

api/models/error.go

@@ -56,14 +56,6 @@ var (
 		code:  http.StatusConflict,
 		error: errors.New("Cannot remove apps with routes"),
 	}
-	ErrDatastoreEmptyAppName = err{
-		code:  http.StatusBadRequest,
-		error: errors.New("Missing app name"),
-	}
-	ErrDatastoreEmptyRoutePath = err{
-		code:  http.StatusBadRequest,
-		error: errors.New("Missing route name"),
-	}
 	ErrDatastoreEmptyApp = err{
 		code:  http.StatusBadRequest,
 		error: errors.New("Missing app"),