[PATCH 00/16] Implement DUN server for oFono

Hi, These patches are based my 6 patches sent on Aug 5th. It implements DUN server logic to manage GPRS context create/destroy per DUN client requests. On DUN client side, you can use 'rfcomm bind 0 xx:xx:xx:xx:xx:xx 1' and then 'gsmdial -n /dev/rfcomm0 -c 1 -a cid -l' to test it. Review comments are welcome! Regards, Zhenhua