improve protected branch to add whitelist support (#2451)

* improve protected branch to add whitelist support

* fix lint

* fix style check

* fix tests

* fix description on UI and import

* fix test

* bug fixed

* fix tests and languages

* move isSliceInt64Eq to util pkg; improve function names & typo

modules/util/compare.go

@@ -0,0 +1,29 @@
+// Copyright 2017 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package util
+
+import "sort"
+
+// Int64Slice attaches the methods of Interface to []int64, sorting in increasing order.
+type Int64Slice []int64
+
+func (p Int64Slice) Len() int           { return len(p) }
+func (p Int64Slice) Less(i, j int) bool { return p[i] < p[j] }
+func (p Int64Slice) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+
+// IsSliceInt64Eq returns if the two slice has the same elements but different sequences.
+func IsSliceInt64Eq(a, b []int64) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	sort.Sort(Int64Slice(a))
+	sort.Sort(Int64Slice(b))
+	for i := 0; i < len(a); i++ {
+		if a[i] != b[i] {
+			return false
+		}
+	}
+	return true
+}