add isclose call close many times
add mutex
fix close err
sync quickstart.
Merge pull request #85 from Unknwon/master

sync quickstart.
fix logrotate close fd before rename file, add a MuxWriter for Logger
Merge pull request #86 from slene/master

fix logrotate
add config to countol if enable hotupdate
fix log delete
fix #87
add HttpServerTimeOut   setting
update to hotupdate's connet timeout
fix cache's bug expird is not changed by get method
change r.ParseMultipartForm  position
fix #89
fix #90
Merge pull request #1 from astaxie/master

全并原作者代码