Revert grpc-ecosystem#708 since it breaks backwards compatibility

The solution for grpc-ecosystem#224 turned out to break backwards
compatibility, so we're going to have to find another
solution for users who desire this behaviour.
Also adds test cases from grpc-ecosystem#760.

runtime/mux.go

@@ -1,10 +1,10 @@
 package runtime
 
 import (
+	"context"
 	"fmt"
 	"net/http"
 	"strings"
-	"context"
 
 	"github.com/golang/protobuf/proto"
 	"google.golang.org/grpc/codes"

runtime/mux_test.go

@@ -183,30 +183,20 @@ func TestMuxServeHTTP(t *testing.T) {
 					ops:    []int{int(utilities.OpLitPush), 0, int(utilities.OpPush), 0, int(utilities.OpConcatN), 1, int(utilities.OpCapture), 1},
 					pool:   []string{"foo", "id"},
 				},
-			},
-			reqMethod: "GET",
-			reqPath:   "/foo/bar",
-			headers: map[string]string{
-				"Content-Type": "application/json",
-			},
-			respStatus:  http.StatusOK,
-			respContent: "GET /foo/{id=*}",
-		},
-		{
-			patterns: []stubPattern{
 				{
 					method: "GET",
 					ops:    []int{int(utilities.OpLitPush), 0, int(utilities.OpPush), 0, int(utilities.OpConcatN), 1, int(utilities.OpCapture), 1},
 					pool:   []string{"foo", "id"},
+					verb:   "verb",
 				},
 			},
 			reqMethod: "GET",
-			reqPath:   "/foo/bar:123",
+			reqPath:   "/foo/bar:verb",
 			headers: map[string]string{
 				"Content-Type": "application/json",
 			},
 			respStatus:  http.StatusOK,
-			respContent: "GET /foo/{id=*}",
+			respContent: "GET /foo/{id=*}:verb",
 		},
 	} {
 		mux := runtime.NewServeMux()

runtime/pattern.go

@@ -144,16 +144,7 @@ func MustPattern(p Pattern, err error) Pattern {
 // If otherwise, the function returns an error.
 func (p Pattern) Match(components []string, verb string) (map[string]string, error) {
 	if p.verb != verb {
-		if p.verb != "" {
-			return nil, ErrNotMatch
-		}
-		if len(components) == 0 {
-			components = []string{":" + verb}
-		} else {
-			components = append([]string{}, components...)
-			components[len(components)-1] += ":" + verb
-		}
-		verb = ""
+		return nil, ErrNotMatch
 	}
 
 	var pos int