subnetcalc

Rewrite of dreibh/subnetcalc in Python

Usage examples:
subnetcalc.py [Address{/{Netmask|Prefix}}]
subnetcalc.py 10.1.1.1
subnetcalc.py 10.1.1.1/24
subnetcalc.py 10.1.1.1/255.255.255.0

Build binary:
pyinstaller subnetcalc.py --onefile