Files of libtiff 4.7.0 copied over the former libtiff folder.
Texlive automake files preserved and corrected to correspond the changes (added files tif_hash_set.c and tif_hash_set.h).
Files tiffconf.h and tif_config.h created manually.
TODO: add generation of the files tiffconf.h and tif_config.h to the common configure process.
