Update 2.7.9

* Fix some NPE
* Remove bugged fix from 2.7.8
* Add Email Subject in config file
* Add Email Text in config file ( define your own email message , do not
support html actually )
* Add Email Base Registration
* Add Captcha System ( with /captcha command )
* Hook with ChestShop
* Hook with Multiverse for Spawn Location fix
* Hook with Notifications plugin
* Add Spanish Translation (thanks to makzk)
* Fix xAuth converter
* Add SALTED2MD5 password hashing : MD5(MD5(plaintext_password) + salt)