Use vfsgen instead of go-bindata (#7080)

* use vfsgen instead of go-bindata

* fix templates

* fix fmt

* vendor vsfgen

vendor/github.com/shurcooL/vfsgen/stringwriter.go

@@ -0,0 +1,27 @@
+package vfsgen
+
+import (
+	"io"
+)
+
+// stringWriter writes given bytes to underlying io.Writer as a Go interpreted string literal value,
+// not including double quotes. It tracks the total number of bytes written.
+type stringWriter struct {
+	io.Writer
+	N int64 // Total bytes written.
+}
+
+func (sw *stringWriter) Write(p []byte) (n int, err error) {
+	const hex = "0123456789abcdef"
+	buf := []byte{'\\', 'x', 0, 0}
+	for _, b := range p {
+		buf[2], buf[3] = hex[b/16], hex[b%16]
+		_, err = sw.Writer.Write(buf)
+		if err != nil {
+			return n, err
+		}
+		n++
+		sw.N++
+	}
+	return n, nil
+}