fix #440
fix #440
modify session module
change a log
beego support new version session
make fix
fix #443
gmfim  add lock. fix #445
#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