* src/icons: Add new Icons, remove old icons.
* src/icons/Makefile.am (EXTRA_DIST): Update accordingly.
* src/dialogs.h: Define ids
* src/dialogs.rc: Include new icons.
* src/gpgoladdin.cpp: Update some function names.
* src/mail.cpp (Mail::update_sigstate): Use tofu validity
from gnupg.
(Mail::get_valid_sig): Removed. Too confusing.
(Mail::is_signed): Constify.
(Mail::is_encrypted): New, similar to is_signed.
(level_4_check): Helper to figure out the correct message
for level 4.
(Mail::get_crypto_summary): New. More differntiated title.
(Mail::get_signature_level): New. defines levels.
(Mail::get_crypto_details): New. Replacement for get_signature_status
(Mail::get_crypto_icon_id): Use levels and new icons.
* src/mail.h: Update accordingly.
* src/ribbon-callbacks.cpp (get_is_crypto): Renamed from
get_is_signed.
(get_sig_label): Use get_crypto_summary.
(get_sig_ttip): Use get_crypto_summary.
(get_sig_stip): Use get_crypto_details.
(get_crypto_icon): Use renamed function.
* src/ribbon-callbacks.h: Update accordingly.