Move X.509 and Openpgp operations into custom packages. Implement more
robust input reading. Do not convert []byte to string unnecessarily.
Finish implementation of X.509 CRL creation.
Add a main loop, move I/O code into io.go, move configuration into config.go.
Use shared.Decode24BitLength instead of manually decoding block lengths.
Fix response block decoding and checksum validation.
Add constants for commonly used byte values and use these in the signer and
the client.