Bring profiles into the modern day

[aarongable]

Overhaul Section 7.1 Profiles, with two goals in mind:

• Removing deprecated pieces of our profiles, such as OCSP and the Internet Security Research Group Organization Name.
• Giving them the same format as the profiles in Section 7.1 of the Baseline Requirements.

Fixes #188
Fixes #304

[aarongable]

Preview the result here: https://github.com/letsencrypt/cp-cps/blob/aarongable-patch-1/CP-CPS.md#7-certificate-crl-and-ocsp-profiles

[jsha]

Diffing the Root CA Certificate section against the corresponding section in the BRs:

• For version, the BRs say "MUST be v3(2)" in the table; this branch refers out to a section.
• issuer: the branch carries over "meaningful CN", but that's not in the BRs. I'd recommend deleting it. Also, the branch says just "ISRG" but some pre-existing roots still spell out "Internet Security Research Group"; I think it makes sense to include both here.
• validity: the BRs refer out to a section; we inline it. Since a goal of this is closely matching the BRs, probably better to put our rules in a section to.
• subject: the language here says it's byte-for-byte identical to issuer, but the BRs have it the other way around: issuer is described as byte-for-byte identical to subject, and subject has the naming description.
• subjectKeyIdentifier - I think this is calculated differently for our old vs new roots and we should include both methods here.