Add a simple network manager

This system command will display, set and save the network
   settings.

   netman show   - Displays the current settings.

   netman update - Will check for a net.cfg file on the SD card.
                   If present, it will update the paramaters,
                   delete the file, and reboot. Using the new settings.

   netman save - Saves the current settings to net.cfg on the SD card.
                 This file shoulf be renamed to preserver it across
                 reboots or editited to chech networkin paramates.

   File format is name<space>value:

   echo DEVICE=eth0           > /fs/microsd/net.cfg
   echo BOOTPROTO=fallback    >> /fs/microsd/net.cfg
   echo IPADDR=192.168.0.4    >> /fs/microsd/net.cfg
   echo NETMASK=255.255.255.0 >>/fs/microsd/net.cfg
   echo ROUTER=192.168.0.254  >>/fs/microsd/net.cfg
   echo DNS=192.168.0.254     >>/fs/microsd/net.cfg

   Valid values for `proto` are `dhcp`, `static`, `falback`
   Both will try dhcp for CONFIG_NETINIT_FALLBACK times
   and fall back to the static address.

   NETMASK - is the network mask.
   IPADDR  - this nodes ip address for static or fall back.
   ROUTER  - The default route.
   DNS     - The address of the dns server.

ROMFS/px4fmu_common/init.d/rcS

@@ -180,6 +180,10 @@ else
 	then
 		param reset_all
 	fi
+	if ver hwtypecmp V5X00 V5X90 V5Xa0
+	then
+		netman update -i eth0
+	fi
 
 	#
 	# Set AUTOCNF flag to use it in AUTOSTART scripts.