Fix QByteArray documentation errors.

Add missing external resource link. Provide constructor documentation.

Change-Id: I6d28a19da5c409dd0e0b48e0f693837b63de38f0
Reviewed-by: Qt Doc Bot <qt_docbot@qt-project.org>
Reviewed-by: Jerome Pasion <jerome.pasion@nokia.com>

src/corelib/doc/src/external-resources.qdoc

@@ -60,3 +60,8 @@
     \externalpage http://www.ietf.org/rfc/rfc3941.txt
     \title RFC 3491
 */
+
+/*!
+    \externalpage http://www.ietf.org/rfc/rfc2045.txt
+    \title RFC 2045
+*/

src/corelib/tools/qbytearray.cpp

@@ -888,6 +888,13 @@ static inline char qToLower(char c)
     \sa operator=()
 */
 
+/*! \fn QByteArray::QByteArray(QByteArrayDataPtr dd)
+
+    \internal
+
+    Constructs a byte array pointing to the same data as \a dd.
+*/
+
 /*! \fn QByteArray::~QByteArray()
     Destroys the byte array.
 */