start a project to refactor email processes

[mgage]

Insure the ability to send email in all languages.
Add the capability of attaching files (with suitable safeguards) including pdfs,pngs
and jpgs for instructions or submitted homework. (This feature has been asked for
frequently and now would be a good time to implement it. It shouldn't be too hard. :-)

Consider using Email::Sender::Stuffer as a simpler version of Email::Sender:Simple.
https://metacpan.org/pod/Email::Stuffer

Consider doing additional refactoring (possibly placed n ProblemUtil.pm)

Email::Sender::Simple is used in three places:
Feedback.pm (feedback to the professor from students)
SendMail.pm (instructor generated email to students)
ProblemUtil.pm (automatically generated notices to instructors)

createEmailSenderTransportSMTP() is created in ContentGenerator.pm and already
refactors the current method for doing transport.
(see email from Tani Wallach about script that works using Stuffer)
lib_WeBWorK_ContentGenerator_Feedback.txt

[taniwallach]

Sending email from users whose name has Unicode characters was fixed in #973

Refactoring and support for attachment is not release critical for WW 2.15.

[drgrice1]

I am closing this. I believe this is all done.