Negative indices don't work as I would expect

[Narkhelek]

If I try to use a negative indice it subtracts from the IP subnet instead of returning an IP from the end of netblock.

For example:

foo1 = ipcalc.Network('192.243.234.0/29')
print foo1[-1]
192.243.233.255

I would expect it to return 192.243.234.7 which is the last IP in the 192.243.234.0/29 netblock.

This may be working as expected but it would be very handy to be able to indices IPs from the end of the subnet moving toward the beginning.

[tehmaze]

This is indeed a bug