... when importing ODF documents.

In CreatePackageEncryptionData(), add a 3rd SHA1 password hash,
PackageSHA1CorrectEncryptionKey, to EncryptionData.

Use it in ZipPackageStream::getDataStream(), which has 3 fall-backs
for SHA1 bugs now.

Also add a CorrectSHA1DigestContext, to be used together with
PackageSHA1CorrectEncryptionKey, and rename the existing one to
StarOfficeSHA1DigestContext, to be used together with the existing
2 PackageSHA1{UTF8,MS1252}EncryptionKey.

The fallback won't be used very often anyway: for the password SHA1
to be wrong, you need a password between 52 and 55 bytes long,
and for the SHA1/1K checksum to be wrong, you need a file
smaller than 1K with compressed size mod 64 between 52 and 55;
all XML files have enough random "chaff" added to be too large.

Test that we can read both correct SHA1 and StarOffice SHA1.

Change-Id: I988fa489b5e40c7657f404f18538f637d54d28f1