lib-dcrypt: Add module_dir setting This is needed for unit tests that require dcrypt, so that they can load backend without installing it first.

lib-dcrypt: enc_key and pw must be NULL on storing unencrypted private key Add tests for password and key encryption, and get_info on them. Also give examples of valid cipher values for password and key encryption in dcrypt.h comment.

lib-dcrypt: fix comment of dovecot format v2 to use colon Version 2 field separator was changed to colon.

lib-dcrypt: drop format from key_load_public

lib-dcrypt: drop format from key_load_private

dcrypt: Use refcounting on keys

lib-dcrypt: dcrypt_key_type_public/private() can no longer fail. Removed unnecessary failure handling.

lib-dcrypt: dcrypt_key_convert_private_to_public() can no longer fail. Removed unnecessary failure handling.

lib-dcrypt: Allow specifying crypto_device (OpenSSL engine).

lib-dcrypt: Fix various problems

lib-dcrypt: Initial implementation