added limit() tests. Closes #476
added limit() tests. Closes #476

austincitylimits/connect,gtomitsuka/connect,mi2oon/connect,khirayama/connect,llwanghong/connect,RickyDan/connect,mi2oon/connect,liuwei9413/connect,khalerc/connect,davehorton/drachtio,qitianchan/connect,senchalabs/connect,lian774739140/connect,RoseTHERESA/connect,wghust/connect,keenwon/connect,behind2/connect,tanveer12332/connect,dkfiresky/connect,chinazhaghai/connect