Update paths in man page to reflect libvirtd code

Updated the paths in the man page to reflect what the code in libvirtd
does. In addition broke out the FILES section into two subsections for
files used when run as root and files used when run as non-root.
Provided information about the defaults that libvirtd uses when running
as non-root and when XDG_CONFIG_HOME and XDG_RUNTIME_DIR are not set in
the environment.

daemon/libvirtd.pod.in

@@ -75,6 +75,8 @@ On receipt of B<SIGHUP> libvirtd will reload its configuration.
 
 =head1 FILES
 
+=head2 When run as B<root>.
+
 =over
 
 =item F<SYSCONFDIR/libvirtd.conf>
@@ -86,11 +88,7 @@ command line using the B<-f>|B<--config> option.
 
 =item F<LOCALSTATEDIR/run/libvirt/libvirt-sock-ro>
 
-The sockets libvirtd will use when B<run as root>.
-
-=item F<$XDG_RUNTIME_DIR/libvirt/libvirt-sock>
-
-The socket libvirtd will use when run as a B<non-root> user.
+The sockets libvirtd will use.
 
 =item F<SYSCONFDIR/pki/CA/cacert.pem>
 
@@ -110,6 +108,41 @@ The PID file to use, unless overridden by the B<-p>|B<--pid-file> option.
 
 =back
 
+=head2 When run as B<non-root>.
+
+=over
+
+=item F<$XDG_CONFIG_HOME/libvirtd.conf>
+
+The default configuration file used by libvirtd, unless overridden on the
+command line using the B<-f>|B<--config> option.
+
+=item F<$XDG_RUNTIME_DIR/libvirt/libvirt-sock>
+
+The socket libvirtd will use.
+
+=item F<$HOME/.pki/libvirt/cacert.pem>
+
+The TLS B<Certificate Authority> certificate libvirtd will use.
+
+=item F<$HOME/.pki/libvirt/servercert.pem>
+
+The TLS B<Server> certificate libvirtd will use.
+
+=item F<$HOME/.pki/libvirt/serverkey.pem>
+
+The TLS B<Server> private key libvirtd will use.
+
+=item F<$XDG_RUNTIME_DIR/libvirt/libvirtd.pid>
+
+The PID file to use, unless overridden by the B<-p>|B<--pid-file> option.
+
+=item If $XDG_CONFIG_HOME is not set in your environment, libvirtd will use F<$HOME/.config>
+
+=item If $XDG_RUNTIME_DIR is not set in your environment, libvirtd will use F<$HOME/.cache>
+
+=back
+
 =head1 EXAMPLES
 
 To retrieve the version of libvirtd: