fix compatibility with leptonica 1.71 and 1.70

git-svn-id: http://tesseract-ocr.googlecode.com/svn/trunk@1126 d0cd1f9f-072b-0410-8dd7-cf729c803f20
fix compatibility of uninstall:  MacOSX rm needs -f instead of --force

git-svn-id: http://tesseract-ocr.googlecode.com/svn/trunk@1127 d0cd1f9f-072b-0410-8dd7-cf729c803f20