A few one-liner fixes. openTunLinux IPV6PREFIX fix is critical.
Merge remote-tracking branch 'upstream/develop' into develop-fixes
Use constant with proper direction (PC->mote) for header byte
Merge branch 'develop-fixes' into develop_kb
Added tun_owsn script to create TUN interface

Forgot to add this script from merge of develop_SW-17_kb branch on 4/27. Also
updated READMEs to describe use of script.