IP masks are now configurable with config file
Merge pull request #6 from ptony82/feature/mask-config

IP masks are now configurable with config file
changes logging names
Merge pull request #7 from ptony82/feature/mask-config

changes logging names
[DEBUG] ipv4 parsing

If user happen to specify ipv4 in config file with less than three
digit at the last 8bit address space, address parsing not work
correctly.
Make it more readable and remove unused codes
Merge pull request #8 from kyuhojeong/ipv4_split

[DEBUG] ipv4 parsing