Update relnotes for 7.3R (first round):
ddb(8) pager support for show_geom*,
deadlock involving malloc(3) and fork(2) fixed,
gptzfsboot added,
zfsboot # of fd increased,
hwpmc added,
s/k8temp/amdtemp/,
pci(4) improvement,
bge(4) panic on shutdown fixed,
cxgb upgraded,
fxp(4)+TSO IP length issue fixed,
nfe(4) improved,
nge(4) improved,
net.inet.ip.fw.default_to_accept added,
NFS client negative pathname lookup cache added,
vfs.flushbufqtarget added,
Bluetooth(3) HCI API support,
btpand(8) -d device name support,
chflags(1) -h bugfix,
cpuset -x option,
dhclient NUL-terminated text bugfix,
fdisk(8) size qualifiers support,
fetch(1) *_TIMEOUT and HTTPS parameters bugfix,
find(1) -L + -delete bugfix,
ktrace(1) new record for sysctl,
fdopendir(3) added,
feature_present(3) added,
man(1) UTF-8 support,
mergemaster now passes -L to mtree(8),
newfs_msdos(8) non-CHS media support,
pkill now ignores itself and ancestors, -a option added,
ps -p option added,
pwd_mkdb -C now checks MAXLOGNAME,
rtld(1) LD_ELF_HINTS_PATH support,
sysinstall(8) comma-separated list of interfaces in netDev,
tzdata2009i,
sendmail 8.14.4, and
pkg_info(1) segfault fix.

Approved by: re (implicitly)