Upgrade of PHPMailer
Added generic 'send_mail()' Function

`send_mail( (string|parse_email array) $emails, (string) $subject, (string) $message, (boolean) $html=false) ? boolean`
Merge branch 'send_mail' of https://github.com/f0o/librenms
Merge branch 'phpmailer' of https://github.com/f0o/librenms