* Options:
- Allow parsing of boolean arguments (arguments with no value).
- Really use the short names.
(Daniel Holbach, Murray Cumming)
* Added filename_display_basename() and filename_display_name().
(Murray Cumming)
* Added setenv() and unsetenv(). (Murray Cumming)
* Use static keyword to prevent exporting private API.
(BenoƮt Dejean)
* input example: Improvements and simplification. (Chris Vine)