Signed-off-by: Avi Kivity <avi@cloudius-systems.com>

Added our copyright statements to some of the files in the top bsd/
directory, and in bsd/porting.

I only added our copyright to files which were completely by us - I did
not attempt to hunt which bsd or solaris files we modified to add our
copyright to them, I don't think this is important (or, we can do this
later).

I also found one header file (uma_stub.h) that had large chunks copied from
freebsd, so I added both the freebsd copyright and ours.

Attempting to put an end to the linux<->freebsd confusion.

kern_accept() used to return a newly allocated sockaddr struct instead
of modifying the given one. this is a porting issue, since we're not
copying the struct to the user when kern_accept finish.

change the calling convention of kern_accept so it'll modify the given
sockaddr struct instead of returning a newly allocated one.

the kern_xxx functions are needed by the linux compatibility layer.

previousely, the len argument weren't handled correctly, it should be returned
to the user and the sockaddr salen should be initialized with the api when
possible.