[BUG] Sort file list case insensitively

- Make the sorting done on the entries list case insensitive.
- Adds integration test.
- Resolves #317

modules/base/natural_sort.go

@@ -5,11 +5,13 @@ package base
 
 import (
 	"math/big"
+	"strings"
 	"unicode/utf8"
 )
 
 // NaturalSortLess compares two strings so that they could be sorted in natural order
 func NaturalSortLess(s1, s2 string) bool {
+	s1, s2 = strings.ToLower(s1), strings.ToLower(s2)
 	var i1, i2 int
 	for {
 		rune1, j1, end1 := getNextRune(s1, i1)

modules/base/natural_sort_test.go

@@ -20,4 +20,10 @@ func TestNaturalSortLess(t *testing.T) {
 	test("a-1-a", "a-1-b", true)
 	test("2", "12", true)
 	test("a", "ab", true)
+
+	// Test for case insensitive.
+	test("A", "ab", true)
+	test("B", "ab", false)
+	test("a", "AB", true)
+	test("b", "AB", false)
 }