Delete returns *BeegoHttpRequest DELETE method.

Get returns *BeegoHttpRequest with GET method.

Head returns *BeegoHttpRequest with HEAD method.

NewBeegoRequest return *BeegoHttpRequest with specific method.

NewDeadCache 实例化DeadCache，每个HTTPServer只对应一个DeadCache.

Post returns *BeegoHttpRequest with POST method.

PostJSON 方法废弃，后面都使用beego的那些方法，beego的httplib做了改动，会复用transport.

Put returns *BeegoHttpRequest with PUT method.

SetDefaultSetting Overwrite default settings.

BeegoHTTPRequest provides more useful methods for requesting one url than http.Request.

BeegoHTTPSettings is the http.Client setting.

DeadCache 死掉的实例缓存.