beego.Context.Abort return immediately

* add common 4XX/5XX HTTP exceptions

add function InsertFilter to replace AddFilter by using int const to determine filter position

pos can be const:
    BeforeRouter = iota
    AfterStatic
    BeforeExec
    AfterExec
    FinishRouter

[orm] QueryTable with nil ptr struct

http.ResponseWriter doesn't implement  WriteCloser interface

The removed code will never be executed, remove it

1，增加QPS的限制
2，增加任务
3，增加healthcheck

so if your web is need auth or release the resoure you can writer the
finish filter

the process exit and the channel info can't flush to console

Update template.go

We can specify "TemplateLeft" and "TemplateRight" but they did not work as these two changes are required.

if have a attack url, the info is

UrlFor(endpoint string, values ...string) string