api: Add go files

I know this is a huge commit, but I can't be bothered to check
this in part by part.

api/domain_update.go

@@ -0,0 +1,59 @@
+package main
+
+import (
+	"net/http"
+)
+
+func domainUpdate(d domain) error {
+	statement := `
+		UPDATE domains
+    SET name=$2, state=$3, autoSpamFilter=$4, requireModeration=$5, requireIdentification=$6
+		WHERE domain=$1;
+	`
+
+	_, err := db.Exec(statement, d.Domain, d.Name, d.State, d.AutoSpamFilter, d.RequireModeration, d.RequireIdentification)
+	if err != nil {
+		logger.Errorf("cannot update non-moderators: %v", err)
+		return errorInternal
+	}
+
+	return nil
+}
+
+func domainUpdateHandler(w http.ResponseWriter, r *http.Request) {
+	type request struct {
+		Session *string `json:"session"`
+		D       *domain `json:"domain"`
+	}
+
+	var x request
+	if err := unmarshalBody(r, &x); err != nil {
+		writeBody(w, response{"success": false, "message": err.Error()})
+		return
+	}
+
+	o, err := ownerGetBySession(*x.Session)
+	if err != nil {
+		writeBody(w, response{"success": false, "message": err.Error()})
+		return
+	}
+
+	domain := stripDomain((*x.D).Domain)
+	isOwner, err := domainOwnershipVerify(o.OwnerHex, domain)
+	if err != nil {
+		writeBody(w, response{"success": false, "message": err.Error()})
+		return
+	}
+
+	if !isOwner {
+		writeBody(w, response{"success": false, "message": errorNotAuthorised.Error()})
+		return
+	}
+
+	if err = domainUpdate(*x.D); err != nil {
+		writeBody(w, response{"success": false, "message": err.Error()})
+		return
+	}
+
+	writeBody(w, response{"success": true})
+}