wzg fixed more file upload..
Merge branch 'master' of https://github.com/jiangzhen1984/V2TechConferenceClient
wzg 初步实现了多文件传送功能，界面需要修改一下，修复了组织列表自动滚动底部，ConversationView中一些图片适配问题
Merge branch 'master' of https://github.com/jiangzhen1984/V2TechConferenceClient