adapted copyright information for SHA and MD5

The SHA and MD5 have been replaced by public domain versions.

Signed-off-by: Marco van Wieringen <marco.van.wieringen@bareos.com>
Like with MD5 only use SHA1 implementation as fallback.

Like what we have done with MD5 the SHA1 implementation included is only
used on platforms where we cannot (or do not want) to use the openssl
SHA1 implementation. We include the right include file via the sha1.h
header. We also no longer build the test sha1sum program as the new SHA1
has no test program buildin anymore.