o #ifdef _KERNEL the fallback definition for DLT_IEEE802_11_RADIO
o fix many comments
o rename antenna stuff and fix units/reference signal
o change IEEE80211_RADIOTAP_DBM_TX_POWER from unsigned 16-bit value
to a signed 8-bit value
o change IEEE80211_RADIOTAP_FLAGS from 16 bits to 8 bits to simplify
padding requirements
o drop IEEE80211_RADIOTAP_TIME
o change IEEE80211_RADIOTAP_ANTENNA from 16 bits to 8 bits
o drop IEEE80211_RADIOTAP_PAD
o add channel flag definitions for outside the kernel so radiotap
doesn't depend on stuff in ieee80211*.h
Obtained from: NetBSD
c6b688c403