cfg80211: clean up includes

cfg80211: clean up includes

Trying to separate header files into net/wireless.h and
net/cfg80211.h has been a source of confusion. Remove
net/wireless.h (because there also is the linux/wireless.h)
and subsume everything into net/cfg80211.h -- except the
definitions for regulatory structures which get moved to
a new header net/regulatory.h.

The "new" net/cfg80211.h is now divided into sections.

There are no real changes in this patch but code shuffling
and some very minor documentation fixes.

I have also, to make things reflect reality, put in a
copyright line for Luis to net/regulatory.h since that
is probably exclusively written by him but was formerly
in a file that only had my copyright line.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>