Merge pull request #7 from ptony82/features/port-cleanup

Features/port cleanup
Support for router mode which uses configuration from config file
On-demand GroupVPN

Add another option to create P2P connection. There used to be one
option that is creating P2P when it login to XMPP.  Now, it can
create P2P when the packet is detected in the tapdevice that is
destined to remote node.

 - On-demand mode is configurable through config file
 - If the connection is inactive certain threshold, it trims the
   connection. This threshold is configurable through config file
Make repeated codes in functions

 -
Merge pull request #8 from ptony82/features/router-mode

Support for router mode which uses configuration from config file
Merge pull request #9 from kyuhojeong/on-demand

On-demand GroupVPN
Update README.md
[DEBUG] GroupVPN does not start connection establishment on persistent mode

 - Should start connection establish on con_req
Merge pull request #10 from kyuhojeong/debug-persistent

[DEBUG] GroupVPN does not start connection establishment on persistent mode