http://stackoverflow.com/questions/15267539/how-to-upload-image-to-server-from-gallery-as-json-on-ios
http://stackoverflow.com/questions/11251340/convert-image-to-base64-string-in-ios/11251478#11251478
iOS upload picture using base64,布布扣,bubuko.com
iOS upload picture using base64
原文地址：http://www.cnblogs.com/forunix/p/3857916.html
