Extensions to the netmap framework - Week 11/12

[Stefano Duo]

Hi,

during these past two weeks i worked on implementing per-slot buffer
offsets, moreover i updated the wiki page. I focused on writing about the
deliverables implementation details, so that if anyone were to continue
working on them, they would have a good descriptions of the inner workings.
Finally i added possible ideas for future contributions.

Project wiki:
https://wiki.freebsd.org/SummerOfCode2018Projects/ExtensionsToNetmap
SVN repository: https://svnweb.freebsd.org/socsvn/soc2018/sduo/

Stefano.