graphics/tesseract: update to 5.0.0

1. Switch OPENMP on for amd64, i386, powerpc64 and powerpc64le - other architectures untested.
2. Remove stale patch-configure.ac, the port uses cmake now.
3. Remove stale patch-src_ccutil_ocrclass.h, that doesn't apply.
4. Manually install libraries used by training tools, they are not installed automatically.