* gpgoladdin.cpp (GetIDsOfNames): Add ID's for mime actions.
  (Invoke): Handle new actions.
  (GetCustomUI): Remove most of the Ribbon UI only leave
  encrypt / sign / start certificate manager buttons.
* src/mailitem-events.cpp (sign_encrypt_item): Renamed to
  do_crypto_on_item.
  (do_crypto_on_item): Do crypto according to draft flags.
  (needs_crypto): New. Check if the mailitem needs crypto at all.
  (Invoke): Pass send when no crypto action is selected.
* src/mapihelp.cpp (get_gpgol_draft_info_flags),
  (set_gpgol_draft_info_flags): New helpers to work with draft info.
* src/mapihelp.h: Declare above functions.
* src/ribbon-callbacks.cpp (message_flag_status): Show a messagebox
  to inform about crypto actions.
  (mark_mime_action): New. Set the draft_info_flags.
  (mime_sign, mime_encrypt): New. Callback functions for outlook.