dtmail: resolve coverity warnings related to uninitialised members in C++ classes

cde/programs/dtmail/libDtMail/RFC/RFCFormat.C

@@ -53,6 +53,7 @@ RFCFormat::RFCFormat(DtMail::Session * session)
 {
     _session = session;
     _is_write_bcc = DTM_FALSE;
+    _use_cr = DTM_FALSE;
 }
 
 RFCFormat::~RFCFormat(void)

cde/programs/dtmail/libDtMail/RFC/RFCMailValues.C

@@ -71,6 +71,7 @@ RFCValue::RFCValue(const char * str, int size) : DtMailValue(NULL)
     _value[size] = 0;
 
     _decoded = NULL;
+    _session = NULL;
 }
 
 RFCValue::RFCValue(const char * str, int size, DtMail::Session *s) : DtMailValue(NULL)

cde/programs/dtmail/libDtMail/RFC/RFCTransport.C

@@ -129,6 +129,9 @@ RFCTransport::RFCTransport(DtMailEnv & error,
     // Set up the handlers so that we are notified when a child
     // process exits and do the right thing.
     signalRegister();
+    
+    _error_proc = NULL;
+    _smd = NULL;
 }
 
 RFCTransport::~RFCTransport(void)