Pynic

Added
- Added setter for name
- Added hardware address validation for both length format
- Added setter for hardware address, but it is working just for 17 length format

Fixed
- Fixed problems with repr and print functions on Python 3.

Changed
- All variables were changed to class properties.

Added
- It was added getter functions to fill the class properties' requirements
- It was added more error checking
- Exported constants, e.g., SIOCGIFFLAGS and SIOCSIFADDR.
- Added getter and setter to flags
- Added getter and setter to running and updown
- Added getter to all variables (some variables are not able to use setters)

Fixed
- Fixed problem with header files in distribution package

Fixed
- Fixed issue with NIC's name when was updated tx and rx on Python 2.

Added
- Added set_inet_addr() method.