Enhancement for issues #3

Add some functionality:

* Add google connect which automatically create a new mailbox (there's some validation by uri,if there's already mailbox with same uri then system won't create a new mailbox)

* raw UI for mailbox
  - list mailbox /mailboxs/
  - add/update  /mailbox | mailbox/1/update
  - mailbox detail  /mailbox/1

demo can be found in : http://192.241.205.252:8000/mailbox for create a new mailbox

for test google connect, please change your /etc/hosts and associate 192.241.205.252 to djibon.server.com