Fixed url.PathUnescape for go1.7

Signed-off-by: Vishal Rana <vr@labstack.com>

echo.go

@@ -45,7 +45,6 @@ import (
 	stdLog "log"
 	"net"
 	"net/http"
-	"net/url"
 	"path"
 	"path/filepath"
 	"reflect"
@@ -435,7 +434,7 @@ func (e *Echo) Static(prefix, root string) {
 
 func static(i i, prefix, root string) {
 	h := func(c Context) error {
-		p, err := url.PathUnescape(c.Param("*"))
+		p, err := PathUnescape(c.Param("*"))
 		if err != nil {
 			return err
 		}

middleware/static.go

@@ -2,7 +2,6 @@ package middleware
 
 import (
 	"fmt"
-	"net/url"
 	"os"
 	"path"
 	"path/filepath"
@@ -76,7 +75,7 @@ func StaticWithConfig(config StaticConfig) echo.MiddlewareFunc {
 			if strings.HasSuffix(c.Path(), "*") { // When serving from a group, e.g. `/static*`.
 				p = c.Param("*")
 			}
-			p, err = url.PathUnescape(p)
+			p, err = echo.PathUnescape(p)
 			if err != nil {
 				return err
 			}

util_go17.go

@@ -0,0 +1,12 @@
+// +build go1.7,!go1.8
+
+package echo
+
+import (
+	"net/url"
+)
+
+// PathUnescape is wraps `url.QueryUnescape`
+func PathUnescape(s string) (string, error) {
+	return url.QueryUnescape(s)
+}

util_go18.go

@@ -0,0 +1,10 @@
+// +build go1.8
+
+package echo
+
+import "net/url"
+
+// PathUnescape is wraps `url.PathUnescape`
+func PathUnescape(s string) (string, error) {
+	return url.PathUnescape(s)
+}