Implement Client configuration

- add mobile date network devices and configuration
- add client configuration via udev
- add GUI under networking tab
- add scripts to handle mobile data devices

config/client_config/ppp0_setpin.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+# in case /dev/ttyUSB0 does not exist, wait for it at most 30 seconds
+let i=1
+while ! test -c /dev/ttyUSB0; do
+  let i+=1
+  if [ $i -gt 2 ]; then
+    logger -s -t setpin "/dev/ttyUSB0 does not exist"
+    exit 3
+  fi
+  logger -s -t setpin "waiting 3 seconds for /dev/ttyUSB0"
+  sleep 3
+done
+# check for pin and set it if necessary
+wvdial pinstatus 2>&1 | grep -q '^+CPIN: READY'
+if [ $? -eq 0 ]; then
+  logger -s -t setpin "SIM card is ready to use :-)"
+else
+  logger -s -t setpin "setting PIN"
+  wvdial pin 2>/dev/null
+fi
+exit 0