radvd.h: remove vestigial privsep_enabled prototype

The privsep_enabled function was removed in commit 793456b (over two years
ago), but this prototype was missed.  This change removes it.
device-bsd44.c: check_ipv6_forwarding not implemented warning

Remove the template code copied from device-linux.c from check_ip6_forwarding
in device-bsd44.c and replace it with a simpler warning that this function
isn't implemented.
device-bsd44.c: disable_ipv6_autoconfig -> set_interface_autoconfig

This function isn't implemented in device-bsd44.c, but keep the function
name the same as it is on linux to help reduce bitrot in device-bsd44.c
privsep-linux.c: move disable_ipv6_autoconfig here

Disabling autoconfig must be done in root context and may have to be called
on interfaces which come up after radvd drops root priveledges, so it needs
to be done in the privsep process.

This actually reuses more code and simplifies things.
logging cleanup

This change makes the logging a bit clearer and makes the logging
a bit more uniformly formatted.
logging cleanup
Merge branches 'logging_changes' and 'issue_33' into 2.5-rc
limit non-ready, unchanged ifaces to 10x normal time

netlink will let us know when to do something with these non-ready
interfaces, so make the timeout on these interfaces much longer.
update CHANGES and configure.ac for v2.5
fix memory leaks exposed by valgrind
gram.y: call yylex_destroy after parse

This cleans up a memory leak in the lexer
privsep-linux.c free username and chrootdir

This isn't really *needed*, but to be OC about memory leaks requires
everything to be freed and to have clean output from valgrind, even
from the privsep process.
recv.c: allocate mhdr.msg_control in the callers

recv_rs_ra was calling malloc and setting a static buffer for this
field.  The memory leak always bothered me.  This change uses
a stack buffer in the callers of recv_rs_ra for this value.

The parameter list is getting a bit long and complicated for this
function, so there's more to do to clean this up.
Merge branch 'valgrind' into v2.5-rc1

Conflicts:
	radvd.h
Update CHANGES with memory leak cleanup notes