LDP spec org update - separation of rules per type

A quick look at the TOC [1] you'd find that the conformance clauses have
been separated into various h2-level sections, the general and HTTP verb
specific ones are now at h3.  Based on feedback recently, editors felt this
would help with clarity.  Additionally considering moving the LDP clients
section within LDP-RS section.  Which I'd like to propose Monday though I
want to validate as believe it was done in reaction to LC comment(s).

[1] - https://dvcs.w3.org/hg/ldpwg/raw-file/default/ldp.html#toc

- Steve Speicher