popt 1.18 Command line option parsing library

This is the popt(3) command line option parsing library. While it is similar to getopt(3), it contains a number of enhancements, including:

- popt is fully reentrant;

- popt can parse arbitrary argv[] style arrays while getopt(3) makes this quite difficult;

- popt allows users to alias command line arguments;

- popt provides convenience functions for parsing strings into argv[] style arrays.