Change S/MIME Message Class handling
* src/olflange.cpp (install_forms): Register new icons * src/mimemaker.cpp (finalize_message): Use SMIME for encryption. * src/revert.cpp (gpgol_mailitem_revert): Use standard classes. * src/mapihelp.cpp (change_message_class_ipm_note_smime) (change_message_class_ipm_note_secure_cex) (string_to_type) (mapi_change_message_class): Split up MultipartSigned and SM.MultipartSigned
This allows us to use better icons which should lead to
less confusion.
Interoperability issues are also addressed by changing
the message class to a value more standard.
- GnuPG-Bug-Id: T4278