Use vfsgen instead of go-bindata (#7080)

* use vfsgen instead of go-bindata

* fix templates

* fix fmt

* vendor vsfgen

vendor/github.com/shurcooL/httpfs/vfsutil/vfsutil.go

@@ -0,0 +1,39 @@
+// Package vfsutil implements some I/O utility functions for http.FileSystem.
+package vfsutil
+
+import (
+	"io/ioutil"
+	"net/http"
+	"os"
+)
+
+// ReadDir reads the contents of the directory associated with file and
+// returns a slice of FileInfo values in directory order.
+func ReadDir(fs http.FileSystem, name string) ([]os.FileInfo, error) {
+	f, err := fs.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	return f.Readdir(0)
+}
+
+// Stat returns the FileInfo structure describing file.
+func Stat(fs http.FileSystem, name string) (os.FileInfo, error) {
+	f, err := fs.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	return f.Stat()
+}
+
+// ReadFile reads the file named by path from fs and returns the contents.
+func ReadFile(fs http.FileSystem, path string) ([]byte, error) {
+	rc, err := fs.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer rc.Close()
+	return ioutil.ReadAll(rc)
+}