Add some notes about rebuilding kdelibs4-dependent ports if using clang.

As mentioned in r322300, clang support has been improved since the update to
4.10.4 a few days ago.

This, however, requires a rebuild of the ports that depend on kdelibs4. Most
of them are covered by the KDE update itself, but those which are not part
of the Software Compilation need to be rebuilt manually to make sure the
previous issues (proper symbol visibility being the most annoying of them)
are solved.

I haven't fully tested all the possible portmaster/portupgrade/pkg commands
myself, so please shout out loud if they're not correct.

In collaboration with:	avilla@

UPDATING

@@ -5,6 +5,35 @@ they are unavoidable.
 You should get into the habit of checking this file for changes each time
 you update your ports collection, before attempting any port upgrades.
 
+20130705:
+  AFFECTS: users of x11/kdelibs4
+  AUTHOR: kde@FreeBSD.org
+
+  The KDE Software Compilation 4.10.4 was committed a few days ago, and
+  version 4.10.5 was committed today.
+
+  They include better support for using clang as the compiler, but that
+  requires recompiling all KDE ports which depend on x11/kdelibs4. Most
+  ports which fall into this category are already part of the KDE Software
+  Compilation and have been updated to version 4.10.5, but those released
+  separately need to be rebuilt manually.
+
+  If you are building your KDE ports with clang, doing the following is
+  recommended:
+
+  # portmaster -r kdelibs-4\*
+    or
+  # portupgrade -fr x11/kdelibs4
+    or
+  # pkg install -fR x11/kdelibs4
+
+  Alternatively, to avoid rebuilding the ports which are part of the 4.10.5
+  update:
+
+  # portmaster -x \*-4.10.5\* -r kdelibs-4\*
+    or
+  # portupgrade -x \*-4.10.5\* -fr x11/kdelibs4
+
 20130703:
   AFFECTS: users of comms/trustedqsl and comms/tqsllib
   AUTHOR: db@FreeBSD.org