* add constants to enums
* HAL update: stops panics, fixes ad hoc-mode beacons, some API
changes
* get and use mac/phy/rf front-end revision codes
* add a custom ath(4) ic_node_getrssi callback which does RSSI
averaging
* do not immediately scan, but re-associate after missing beacons.
* bug fix: don't if_init after detach.
* HAL diagnostics ioctl, SIOCGATHDIAG
* send DS parameters element in beacons
* const-ify some pointers
* consolidate rx-filter settings into ath_calcrxfilter
* abstract FreeBSD `ticks', NetBSD `hardclock_ticks' with ATH_TICKS()
* misc. other changes
