Merge pull request #1 from firefox007/master

move pigeon to github
modify readme
Merge pull request #2 from bensonyang/master

modify readme
重构pigeon客户端逻辑，修改为filter chain实现
添加服务端处理Process Filter类实现
将InvocationFilter分拆为InvokeFilter和ProcessFilter
将InvocationFilter分拆为InvokeFilter和ProcessFilter
重构request的context设置方式
Merge pull request #6 from liuliliujian/master

暂时没大的问题，由于是重构先合并进来，最后在统一确保代码没问题；
add DpsfThreadPoolExecutor
remove bin