dbee 7.x-2.0

Important warning : Perform a database backup before installing this release : If thinks goes wrong you may loose all your users email address !!

- Migration from previous database structure ('dbee' table) to new structure based on altering the core 'users' table (Use the same structure than the Block Class v7.x-2.x module).
- Improvements on the dbee_query_alter() function. Handle all operators now, 'mail' and 'init' fields, searching mails usings wildcards. Thanks to thoses improvements, the user search core functions are not altered anymore.
- The option disabling all users decryption concerns all queries now, not only the users search page.
- Improving performance on decrypting/encrypting users.