GetHosts() iterates over all the hosts it has in memory, and copies
them to a buffer. The buffer length is calculated by iterating over
all the hosts and adding up all of their combined length. There is a
potential integer overflow, if there are lots and lots of hosts (with
a combined length of > ~4 gig). This should be possible by repeatedly
calling ProcChangeHosts() on 64bit machines with enough memory.

This patch caps the list at 1mb, because multi-megabyte hostname
lists for X access control are insane.

v2: backport to nx-libs 3.6.x (Mike DePaulo)
v3: human-readable version of "1 MB" (Mihai Moldovan)
Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>

Conflicts:
	os/access.c