Log Message:
Update to 0.3.1

Changelog:
0.3.0 - 0.3.1

* Fix crash when NULL is passed as input stream.
- Use symbol visibility on Linux. The library only exports public functions
  now.
- Fix various crashes and hangs when reading broken files found with the
  help of american-fuzzy-lop.
- Fix some warnings found by Coverity.
- Make --help output of all command line tools more help2man-friendly.