Remove all of the remaining libcrypt code.

Remove all of the remaining libcrypt code.

Completing the removal of libcrypt, delete all of its actual code.
This patch contains only file removals:

git rm -r crypt
git rm include/crypt.h
git rm $(find sysdeps -name libcrypt.abilist)
git rm $(find sysdeps -name fips-private.h)
git rm $(find sysdeps -name 'md5-*' -o -name 'sha256-*' -o -name 'sha512-*')

For this patch (not the earlier ones, I'd still be waiting) I ran the
complete testsuite and found no *new* failures.  26 tests are failing
on my machine due to probable environment issues, but they were all
failing on trunk before I started making changes, and none of them
appear to have anything to do with this patchset.