Amend the missing documentation for the from*() static overloads

c951908bc201afa59402967d50fa926212845fae sneaked in without adding documentation
to those public static methods. Hence, the public documentation online for those
methods appear to be empty.

More importantly, they have been missing the indication that the introduction
took place in Qt 5.0.

Change-Id: I3ca3fa57a96e28e2d64d0af28159d8bda9cbe71a
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

src/corelib/tools/qstring.cpp

@@ -4094,6 +4094,13 @@ QString::Data *QString::fromAscii_helper(const char *str, int size)
     \sa toLatin1(), fromUtf8(), fromLocal8Bit()
 */
 
+/*!
+    \fn QString QString::fromLatin1(const QByteArray &str)
+    \overload
+    \since 5.0
+
+    Returns a QString initialized with the Latin-1 string \a str.
+*/
 
 /*! \fn QString QString::fromLocal8Bit(const char *str, int size)
     Returns a QString initialized with the first \a size characters
@@ -4106,6 +4113,14 @@ QString::Data *QString::fromAscii_helper(const char *str, int size)
 
     \sa toLocal8Bit(), fromLatin1(), fromUtf8()
 */
+
+/*!
+    \fn QString QString::fromLocal8Bit(const QByteArray &str)
+    \overload
+    \since 5.0
+
+    Returns a QString initialized with the 8-bit string \a str.
+*/
 QString QString::fromLocal8Bit_helper(const char *str, int size)
 {
     if (!str)
@@ -4138,6 +4153,15 @@ QString QString::fromLocal8Bit_helper(const char *str, int size)
     \sa toAscii(), fromLatin1(), fromUtf8(), fromLocal8Bit()
 */
 
+/*!
+    \fn QString QString::fromAscii(const QByteArray &str)
+    \deprecated
+    \overload
+    \since 5.0
+
+    Returns a QString initialized with the string \a str.
+*/
+
 /*! \fn QString QString::fromUtf8(const char *str, int size)
     Returns a QString initialized with the first \a size bytes
     of the UTF-8 string \a str.
@@ -4159,6 +4183,14 @@ QString QString::fromLocal8Bit_helper(const char *str, int size)
 
     \sa toUtf8(), fromLatin1(), fromLocal8Bit()
 */
+
+/*!
+    \fn QString QString::fromUtf8(const QByteArray &str)
+    \overload
+    \since 5.0
+
+    Returns a QString initialized with the UTF-8 string \a str.
+*/
 QString QString::fromUtf8_helper(const char *str, int size)
 {
     if (!str)