Create OCSP Request
Create OCSP Response
Create OCSP Responder
Add rudimentary OCSP response status & nonce parsing

The next steps from here would be to refactor ASN.1 definitions out from
Response to separate classes. Response parsing should also be done once
per object construction.
Move OCSP & X509 ASN.1 mapping to separate classes
Refactor Responder's process creation method to separate method
Refactor Responder's request making to a separate method
Remove ASN.1 notation and link to relevant specs instead
Do some basic response validity checking in Response constructor

Probably not the best place to do this, but works for now.
Merge branch 'ocsp'