* src/network_driver.c (networkEnableIpForwarding): This function
would always return 1 (success).  Now it returns 0 upon write or
close failure, being careful to preserve any errno from a write failure.
Add comments.

storage XML to libvirtd, which was saved in /etc/libvirt/storage.  On subsequent
stop/start of libvirtd, because of another bug , an
error wasn't being set properly in an error path, so libvirtd was SEGV'ing in
storage_conf.c:virStoragePoolObjLoad when trying to dereference the NULL err
returned from virGetLastError().  Make this more robust against errors by always
doing "err ? err->message : NULL" in the printf.  I looked around the tree and
found a couple of other places that weren't guarded, so this patch fixes them as
well.
Signed-off-by: NChris Lalancette <clalance@redhat.com>

POTFILES.in.  Add it there, and then fix up one warning about included
c-ctypes.h that wasn't being used.
Signed-off-by: NChris Lalancette <clalance@redhat.com>