update to Leptonica 1.71
Merge pull request #1 from tweea/master

Update to Leptonica 1.71
Merge branch 'master' of https://github.com/tesseract4java/tesseract-vs2013 into feature/leptonical-1.7.1
Merge branch 'feature/leptonical-1.7.1' into develop
Merge branch 'release/Leptonica_1.7.1_(tesseract_3.04)'