Minor doc improvements.

Change-Id: Ic14cefcf935fea822c581013f437ae61b820ddd9
Reviewed-by: Giuseppe D'Angelo <dangelog@gmail.com>
Reviewed-by: Casper van Donderen <casper.vandonderen@nokia.com>
Reviewed-by: Shane Kearns <shane.kearns@accenture.com>

src/network/ssl/qsslcertificateextension.cpp

@@ -138,15 +138,24 @@ QSslCertificateExtension::QSslCertificateExtension()
 {
 }
 
+/*!
+    Constructs a copy of \a other.
+ */
 QSslCertificateExtension::QSslCertificateExtension(const QSslCertificateExtension &other)
     : d(other.d)
 {
 }
 
+/*!
+    Destroys the extension.
+ */
 QSslCertificateExtension::~QSslCertificateExtension()
 {
 }
 
+/*!
+    Assigns \a other to this extension and returns a reference to this extension.
+ */
 QSslCertificateExtension &QSslCertificateExtension::operator=(const QSslCertificateExtension &other)
 {
     d = other.d;