Handle ERANGE from getpwnam_r / getgrnam_r

These functions return ERANGE if the supplied buffer is too small to
fit a line.  Try doubling the buffer a few times until it works.
Convert the nodeid byte order to be aligned with network order

When using corosync with clear_node_high_bit setting to yes,
the highest bit is cleared.  When all the cluster nodes are in
one subnet, we probably configure the IP addresses as follows:

node1: 147.2.207.64
node2: 147.2.207.192

If the byte order of the nodeid is little endian, wiping off the
highest bit will make the two nodes have the same nodeid!

This patch fixes this by converting the nodeid to network order.

Signed-off-by: Xia Li <xli@suse.com>
Reviewed-by: Jan Friesse <jfriesse@redhat.com>