[gmime] Updated PORTING

[Jeffrey Stedfast <fejj src gnome org>]

commit 6d3f5fc61e44062e6678d73618a4a60c2e2ba98b
Author: Jeffrey Stedfast <jestedfa microsoft com>
Date:   Sun Feb 19 09:00:21 2017 -0500

    Updated PORTING

 PORTING |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/PORTING b/PORTING
index 19e3ef1..2d2e8e8 100644
--- a/PORTING
+++ b/PORTING
@@ -90,6 +90,10 @@ Porting from GMime 2.6 to GMime 3.0
 - GMimeCryptoContext's encrypt, decrypt, and verify methods now all take a flags argument
   that can enable additional features (see above examples).
 
+- g_mime_crypto_context_sign() now takes a boolean 'detach' argument that specifies whether
+  or not to generate a detached signature. To get the old behavior, pass TRUE as the
+  detach argument.
+
 - g_mime_crypto_context_decrypt_session() has been merged with
   g_mime_crypto_context_decrypt() and so the decryot method now takes a session_key
   argument that is allowed to be NULL.