Updating CMIP6 Guide for data node managers and data users pages

[durack1]

We have a number of WIP and CDNOT documents that require updating to bring this inline with current expectations for CMIP6 ESGF nodes and their processes around data replication and retraction of errata datasets.

Some linked documents:
ESGF Tier 1 and Tier 2 Node Site Requirements
https://esgf.llnl.gov/esgf-media/pdf/ESGFTier1and2NodeSiteRequirement-V5.pdf (pdf)
https://docs.google.com/document/d/1ukp5Wh4jeN_P2iT0IRETIjBCAcwDzD0aEWYx5tTjess/edit

Earth System Grid Federation Policies & Guidelines
https://drive.google.com/drive/folders/0Bx0mgzQ5ymkNUmN6ZGZQNFd3a28?resourcekey=0-_2eKGQVsiaRzYndI5A1ZGg (host folder)

Some proposed changes
master...matthew-mizielinski:matthew-mizielinski-CMIP6_guide_updates

Pinging @matthew-mizielinski @sashakames @KatharinaBerger @taylor13