Add revert support for PGP MulitpartEncrypted
* src/mimemaker.c (restore_msg_from_moss): Create a mosstmpl attachment. Currently only works for PGP MultipartEncrypted. * src/mimemaker.h: Add prototype. * src/oomhelp.h: Add DASL for attachment MIME tag. * src/revert.cpp (finalize_mapi): Dont restore message class. (gpgol_mailitem_revert): Collect info first. Then work. Handle MOSS attachments. Do Magic.
For S/MIME we will want to add an option to also restore the
message class. The important thing here is how the message
class is mangled to trigger the SMIME.MultipartSigned behavior
without visibly changing the icon in the message list.