added user independent sections and started db migration work

pkg/db/helper.go

@@ -4,10 +4,11 @@ package db
 
 import (
 	"crypto/sha256"
+	"git.giftfish.de/ston1th/gowiki/pkg/core"
 	"time"
 )
 
-var reservedUsers = []string{
+var reservedNames = []string{
 	"blacklist",
 	"login",
 	"logout",
@@ -27,13 +28,18 @@ func hasTrimPrefix(s, prefix string) (string, bool) {
 	return s, false
 }
 
-func reservedUser(username string) bool {
-	for _, v := range reservedUsers {
-		if username == v {
-			return true
-		}
+func addOrRemove(s string, a []string) []string {
+	i, _ := core.Contains(s, a)
+	switch i {
+	case -1:
+		return append(a, s)
+	case 0:
+		return a[1:]
+	case len(a):
+		return a[:i]
+	default:
+		return append(a[:i], a[i+1:]...)
 	}
-	return false
 }
 
 func validatePassword(pw string) (b []byte) {