New function hash to calculate MD{2/4/5} and SHA{1,244,256,384,512} hash values. * bootstrap.conf: include needed GNULIB functions. * libinterp/dldfcn/hash.cc: new hash value calculating function. * libinterp/dldfcn/module-files: add hash.cc to build system. * scripts/deprecated/md5sum.m: new function perserving interface as md5sum.cc. * scripts/deprecated/module.mk: add md5sum.m to build system. * libinterp/corefcn/md5sum.cc: removed and replaced by m-file. * libinterp/corefcn/module.mk: removed md5sum.cc from build system. * liboctave/util/oct-md5.h: removed unneeded interface header. * liboctave/util/oct-md5.cc: removed unneeded interface code. * liboctave/util/module.mk: removed oct-md5.h and oct-md5.cc from build system. * NEWS: add hash to new functions for 4.2. * doc/interpreter/system.txi: replace md5sum with hash in the manual. * scripts/miscellaneous/warning_ids.m: removed orphaned entry.