#436 support insert multi
update sessionRelease
1. mysql fix last access time not update
2. mysql & redid Release when data is empty
3. add maxlifetime distinct Gclifetime
support send mail
add attach file
add cookie test
reset cache connection to nil, if err isio.EOF

* this will support auto-connection
align memcache operations with redis
Merge pull request #454 from pengfei-xue/develop

support redis cache auto connection
fix #453
Update beego.go
#441 fix detect timezone in mysql
use connection pool for redis cache
remove mutex
Merge pull request #457 from luxuchu/patch-1

fix #453
add a empty fake config Initialize AppConfig to avoid nil pointer runtime error.
fix SessionRegenerateID should release old SessionStore and release new SessionStore in router.go
Merge pull request #460 from pengfei-xue/develop

use connection pool for redis, support auto connection
Removed unnecessary code for appengine
Merge branch 'develop' of https://github.com/astaxie/beego

Conflicts:
	beego.go
	session/sess_redis.go
	session/session.go