always enable explicitlink for all versions of freebsd.

git-svn-id: http://root.cern.ch/svn/root/trunk@6627 27541ba8-7e3a-0410-8455-c3a389f83636

configure

@@ -680,7 +680,7 @@ fi
 ### echo %%% Explicitlink - explicitly link with all dependent libraries
 #
 case $platform in
-freebsd4|aix*|win32*)
+freebsd*|aix*|win32*)
     enable_explicitlink="yes"
     ;;
 esac