adds a folder with some debug tools

adds a folder with some debug tools

This commit includes:
- a simple perl netconf client terminal for testing RPCs.
 It eases the hello handshake and can load custom capabilities from an
 external xml file.
- a perl TCP SSH netconf hijacking proxy for debug purposes.
 It allows to unencrypt and log netconf messages/exchanges between the
 contoller and managed netconf devices.
 Exchanges between both ends (eg. capabilities) are altered according to
 the modifiable rules specified inside the script. This can be useful to
 debug netconf devices and make them work with ODL when they do not send
 the required parameters expected by the controller.
 An option allows to disable this default behavior and turn this script
 into a simple netconf TCP SSH proxy.

Change-Id: Ib6f4ca5c234f4bd97e352cc37dc1a2dff7d8d228
Signed-off-by: guillaume.lambert <guillaume.lambert@orange.com>