Redefeind interfaces; Added better modelled data strauctures

Router interface has been redefined which fits better with what we are
looking for.

Routing table now offers a comprehensive set of information about its
entries which will make up for rich queries in the future

Query interface has been defined to enable current basic and more
advanced queries in the future.

router/router.go

@@ -2,25 +2,32 @@
 package router
 
 import (
-	"errors"
-
 	"github.com/micro/go-micro/registry"
 )
 
+var (
+	// DefaultRouter returns default micro router
+	DefaultRouter = NewRouter()
+)
+
 // Router is micro network router
 type Router interface {
 	// Initi initializes Router with options
 	Init(...Option) error
 	// Options returns Router options
 	Options() Options
-	// AddRoute adds new service route
-	AddRoute(*Route, ...RouteOption) error
-	// RemoveRoute removes service route
-	RemoveRoute(*Route) error
-	// GetRoute returns list of routes for service
-	GetRoute(*Service) ([]*Route, error)
-	// List returns all routes
-	List() ([]*Route, error)
+	// Add adds new entry into routing table
+	Add(*Entry, ...RouteOption) error
+	// Remove removes entry from the routing table
+	Remove(*Entry) error
+	// Update updates entry in the routing table
+	Update(*Entry) error
+	// Lookup queries the routing table and returns matching entries
+	Lookup(Query) ([]*Entry, error)
+	// Table returns routing table
+	Table() *Table
+	// Address is Router adddress
+	Address() string
 	// String implemens fmt.Stringer interface
 	String() string
 }
@@ -28,22 +35,21 @@ type Router interface {
 // Option used by the Router
 type Option func(*Options)
 
-var (
-	DefaultRouter = NewRouter()
+// RouteOption is used by Router for adding routing table entries
+type RouteOption func(*RouteOptions)
 
-	// Not found error when Get is called
-	ErrNotFound = errors.New("route not found")
-)
+// QueryOption is used to defined routing table lookup query
+type QueryOption func(*QueryOptions)
 
 // NewRouter creates new Router and returns it
 func NewRouter(opts ...Option) Router {
-	// set Registry to DefaultRegistry
-	opt := Options{
+	// router registry to DefaultRegistry
+	ropts := Options{
 		Registry: registry.DefaultRegistry,
 	}
 
 	for _, o := range opts {
-		o(&opt)
+		o(&ropts)
 	}
 
 	return newRouter(opts...)