improve xvfb scripts
diff --git a/releng.control/xvfb-auth.cfg b/releng.control/xvfb-auth.cfg
new file mode 100644
index 0000000..90cb409
--- /dev/null
+++ b/releng.control/xvfb-auth.cfg
@@ -0,0 +1,2 @@
+localhost
+local:
diff --git a/releng.control/xvfb-start.sh b/releng.control/xvfb-start.sh
index 4d739be..9a1f85c 100644
--- a/releng.control/xvfb-start.sh
+++ b/releng.control/xvfb-start.sh
@@ -27,7 +27,7 @@
XVFBSCREEN=${BUILD_HOME}/tmp
mkdir -p ${XVFBSCREEN}
-Xvfb :$DISPLAYNUMBER -screen 0 1600x1200x16 -fbdir "${XVFBSCREEN}" -fp "${XVFBFONTPATH}" -ld 10240 -ls 1024 -lf 20 -to 60 -reset -bs &
+Xvfb :$DISPLAYNUMBER -screen 0 1600x1200x16 -fbdir "${XVFBSCREEN}" -fp "${XVFBFONTPATH}" -ld 10240 -ls 1024 -lf 20 -to 60 -reset -bs -auth ${RELENG_CONTROL}/xvfb-auth.cfg &
XVFBPID=$!
echo $XVFBPID > ccxvfb.pid