asn1: Add OID for Blowfish CBC

The OID (1.3.6.1.4.1.3029.1.2) is technically not correct, the correct
one is (1.3.6.1.4.1.3029.1.1.2).  Every other library or tool (like OpenSSL)
uses the incorrect one so we do the same.

References #740.
pkcs5: Add support for PBES2 encryption schemes other than 3DES

This allows using e.g. AES for PKCS#8 and PKCS#12 files.

Some legacy schemes defined in RFC 2898 are not supported (like RC2).

Fixes #740.