Email-created reply including reply preamble

[techAPJ (Arpit Jalan)]

Should be fixed via:

Better email reply parsing

There are many open bugs on meta related to incorrect email reply parsing and I have been looking into them since past few days. Almost everytime the fix is to correct/modify something in GitHub’s email_reply_parser library. The GitHub’s email_reply_parser library is now abandoned. The last commit was over a year ago, and there are many open issues / pull requests. I propose that we include the email_reply_parser in core Discourse email library so that we can customize it as per our requireme…