6LowPAN mesh-based network support for mbedConnectorInterface. The Atmel-based mbed 6LowPAN shield is the assumed network hardware.

Dependencies:   libnsdl Nanostack_lib

This pull request has been rejected by Doug Anson

registration changes

fix NSP_registration() to only do update if called and the EP is already registered, also needed to update sn_nsdl.c in libNsdl to return network error status from sn_nsdl_register_endpoint()