Fix recovery middleware to render gitea style page. (#13857)

* Some changes to fix recovery

* Move Recovery to middlewares

* Remove trace code

* Fix lint

* add session middleware and remove dependent on macaron for sso

* Fix panic 500 page rendering

* Fix bugs

* Fix fmt

* Fix vendor

* recover unnecessary change

* Fix lint and addd some comments about the copied codes.

* Use util.StatDir instead of com.StatDir

Co-authored-by: 6543 <6543@obermui.de>

vendor/github.com/unrolled/render/fs.go

@@ -0,0 +1,21 @@
+package render
+
+import (
+	"io/ioutil"
+	"path/filepath"
+)
+
+type FileSystem interface {
+	Walk(root string, walkFn filepath.WalkFunc) error
+	ReadFile(filename string) ([]byte, error)
+}
+
+type LocalFileSystem struct{}
+
+func (LocalFileSystem) Walk(root string, walkFn filepath.WalkFunc) error {
+	return filepath.Walk(root, walkFn)
+}
+
+func (LocalFileSystem) ReadFile(filename string) ([]byte, error) {
+	return ioutil.ReadFile(filename)
+}