消滅時效 請求權 一般消滅時效期間 與土地相關權利之消滅時效期間 30年消滅時效期間 消滅時效期間之起算與最高期限 消滅時效期間協議之不容許性 消滅時效期間之停止進行 不完成與重新起算 消滅時效之法律效果 時效完成後之抵銷與留置權行使 Limitation Claim Standard limitation period Limitation period in the case of rights to land 30-year limitation period Beginning of the standard limitation period and maximum periods Inadmissibility of agreements on limitation Suspension Suspension of expiration and recommencement of the limitation period Legal consequences of limitation Set-off and right of retention after limitation has occurred