ieee802154: introduce constant for default PAN id
ccnl: adapt for 802154 devices
ccnl: fix argument passing in example app
ccn: add line breaks if limit was exceeded
ccnl: convert C++ comments into C style comments
examples:rpl_udp updated `README.md` on using the build parameters
Merge pull request #2192 from BytesGalore/rpl_addition_to_readme

examples:rpl_udp updated `README.md` on using the build parameters
Merge pull request #2024 from OlegHahm/ccnl_802154

ccn-lite: fixes for working with IEEE 802.15.4 radios