server updates (#566)

* server updates

- improved route create/update validation/defaults
- improved/added route test cases

* cleanup

* negative concurrency check

api/models/app.go

@@ -87,5 +87,6 @@ func (a *App) UpdateConfig(patch Config) {
 }
 
 type AppFilter struct {
+	// An SQL LIKE query. Empty does not filter.
 	Name string
 }