Added Italian translations for some plugins and FIXED some English ones 

Added Italian translations for:
* 'auth.remote_ajxp'
* 'auth.serial'
* 'auth.smb'
* 'auth.sql'
* 'boot.conf'
* 'conf.serial'
* 'conf.sql'
* 'core.ajaxplorer'
* 'core.auth'

Also, fixed some little problem with English ones in:
* 'auth.sql'
* 'conf.sql'
* 'access.ftp'
* 'action.updater'
* 'auth.cmsms'
* 'auth.ldap'
* 'auth.smb'
* 'core.conf'
* 'log.sql'