cpp: Add get / set Sender API

* cpp/src/context.cpp, cpp/src/context.h (Context::setSender),
(Context::getSender): Add simple wrappers.

lang/cpp/src/context.cpp

@@ -466,6 +466,16 @@ Error Context::setEngineHomeDirectory(const char *home_dir)
     return Error(gpgme_ctx_set_engine_info(d->ctx, gpgme_get_protocol(d->ctx), filename, home_dir));
 }
 
+Error Context::setSender (const char *sender)
+{
+    return Error(gpgme_set_sender(d->ctx, sender));
+}
+
+const char *Context::getSender ()
+{
+    return gpgme_get_sender(d->ctx);
+}
+
 //
 //
 // Key Management

lang/cpp/src/context.h

@@ -304,6 +304,10 @@ public:
     GpgME::Error startSigning(const Data &plainText, Data &signature, SignatureMode mode);
     SigningResult signingResult() const;
 
+    // wrapper for gpgme_set_sender
+    const char *getSender();
+    GpgME::Error setSender(const char *sender);
+
     //
     // Encryption
     //