Merge branch 'release/v3.03'
added patch for tesseract
Update README.md

Added notes on how to build tesseract itself and noted the relevant licenses for each project.
Update README.md

Fixed typo
Ensure `png_libpng_ver` is defined
Remove space in patch filename

This way it is easier to apply
Adjust README
Merge pull request #2 from tesseract4java/master

Ensure `png_libpng_ver` is defined