[imp] Delivery Confirmation / Read Receipt Patch

[Michael M Slusarz]

Quoting rmalloy at meridianschools.org:

| The patch below separates the delivery confirmation conand read receipt
| requests in the compose window. I also added a section to preferences to
| specify default behavior. Note, the Honor read receipts functionality
| isn't complete yet.

Modified and committed.  The parts dealing with sending the read receipts
will not be implemented until all code is available.

michael

______________________________________________
Michael Slusarz [slusarz at bigworm.colorado.edu]
The University of Colorado at Boulder