NucleusCMS patch: use UTF-8 base64 to encode email subject
The emails sent by NucleusCMS (e.g. new comment notification) didn't encode the subject, but just put the raw text there. For english language file, that's OK. But for other languages such as Chinese, it's not that good. It will produce garbled text on the subject (but not always garbled, weird).
So I wrote this patch to resolve this problem. Google tell me that if I want to encode an email subject in PHP, I should use the mb_encode_mimeheader() function. But Dreamhost just didn't provide any mb_ functions in PHP. I dug more about email subject encoding, and found that a hardcoded base64 should just do the trick. As the original sending mail code in NucleusCMS hardcoded UTF-8 in the Content-Type, I assume that hardcode UTF-8 in the subject is fine, too.
