an attachment Content-ID and message body content-type

[GoogleCodeExporter]

In order to support the HTML with embedded images emails, it is necessary to 
pass a Content-ID for attachments.
Also, message body has to be "multipart/related" (rather than multipart/mixed) 
or an email client (outlook or thunderbird) would show the body of the email 
split.

The proposed patch allows:
* specify Content-ID for attachments (passed as fifth parameter)
* specify message body content type (introduced -content-type switch)

the switch name is pretty long, so feel free to change it to whatever you find 
suitable.

Also the issue with not initializing attachment_name is fixed by the patch.

Original issue reported on code.google.com by skalogry...@gmail.com on 4 Nov 2013 at 6:13

Attachments:

• patch.zip

[GoogleCodeExporter]

Original comment by muq...@gmail.com on 5 Nov 2013 at 1:08

• Changed state: Accepted

[GoogleCodeExporter]

Patch is applied. test directory has a HTML file and test image to demonstrate 
the functionality of embedding an image in the HTML file while sending the mail.

Original comment by muq...@gmail.com on 6 Nov 2013 at 10:56

[GoogleCodeExporter]

Original comment by muq...@gmail.com on 7 Dec 2013 at 5:39

• Changed state: Done