New utility function

Portable declaration of stdin/out/err fixed, minor refactorings, wiki…

… page, documentation extended

Some bugs in README.md fixed

Bug in README.md fixed and README removed

- Bug in command of compiling/linking w/ f90getopt lib fixed

Version 1.0.1

- Longopt bug fixed
  caused infinite error loop when unknown longopt has a equal sign or
  a unkwnow longopt follows a known one
- Minor refactoring (NO change in API)

Version 1.0.0

- Added support for equal sign (=) in long options, like --beta=2.0
- Error messages are displayed on stderr (not stdout)

Version 0.9.0

Almost finished. Equal sign recognition in longoption (logopt=arg) is missing for v1.0